Security handling for rrc resume from inactive state

ABSTRACT

A communication system including a host computer is provided herein. The host computer may include processing circuitry configured to provide user data and a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE). The cellular network comprises a base station having a radio interface and base station processing circuitry. The base station processing circuitry configured to store a previously active security context for the UE, receive from the UE an RRCResumeRequest message including a security token, generate a temporary security context for the UE, use the temporary security context to verify the security token, send an RRC message to the UE, if no response to the RRC message is received from the UE, discard the temporary security context and retrieve the previously active security context. Thereafter, the base station transmits the user data for a host application.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/721,410, filed Dec. 19, 2019, which is a continuation of U.S. patentapplication Ser. No. U.S. 16/386,077, filed Apr. 16, 2019, which claimsthe benefit of U.S. Provisional App. No. 62/657,967, filed Apr. 16,2018, the disclosures of which are incorporated by reference herein intheir entirety.

TECHNICAL FIELD

The present invention relates generally to wireless communicationnetworks and in particular to systems and method for maintainingsynchronization between a wireless device and a network when thewireless device resumes from an inactive state.

BACKGROUND

Wireless communication networks, enabling voice and data communicationsto wireless devices, are ubiquitous in many parts of the world, andcontinue to advance in technological sophistication, system capacity,data rates, bandwidth, supported services, and the like. A basic modelof one type of wireless network, generally known as “cellular,” featuresa plurality of generally fixed network nodes (known variously as basestation, radio base station, base transceiver station, serving node,NodeB, eNodeB, eNB, gNB, and the like), each providing wirelesscommunication service to a large plurality of wireless devices (knownvariously as mobile terminals, User Equipment or UE, and the like)within a generally fixed geographical area, known as a cell or sector.

Wireless communications propagate between network nodes, such as a basestation and a UE, as information modulated onto radio frequency (RF)carrier signals, which are transmitted by one node across an airinterface, and received and demodulated by the other node. Because themedium is necessarily open (as opposed to a copper wire or opticalfiber, which can be physically secured), security is a primary concern,and security features are designed into the technical specificationsthat govern network operation. For example, most user plane signals(those carrying user data, such as voice, video, text, images, and thelike) are encrypted. Many control plane signals (those related totechnical operation of the network, often referred to as “overhead”) areintegrity protected, meaning that the contents are not encrypted;however, cryptographic means ensure the receiving node can unambiguouslyauthenticate the identity of the transmitting node. Both encryption andintegrity protection are cryptographic operations which rely on thegeneration and use of various “keys,” or unique data that are known (orderivable) only by legitimate parties to the communication.Cryptographic operations only work if the different parties use thesame, or compatible, keys.

Radio Resource Control States in LTE and NR

Radio Resource Control (RRC) is an air interface protocol used in the3^(rd) generation (3G) mobile cellular wireless network protocolUniversal Mobile Telecommunications System (UMTS), as well as the 4^(th)generation (4G) protocol, Long Term Evolution (LTE). Modifications toRRC are proposed for the 5^(th) generation (5G) protocol, New Radio(NR). The Third Generation Partnership Project (3GPP) specifications forUMTS RRC are in Technical Standard (TS) 25.331, and for LTE are in TS36.331.

In LTE, two general RRC modes are defined for a wireless device, or UserEquipment (UE): RRC_IDLE and RRC_CONNECTED. Within the RRC_CONNECTEDmode, a UE transitions between further RRC states, each having lowerpower consumption, based on inactivity timers. The RRC_CONNECTED modestates for LTE are CELL-DCH (Dedicated Channel), CELL_FACH (ForwardAccess Channel), CELL_PCH (Cell Paging Channel) and URA_PCH (UTRANRegistration Area, or URA, Paging Channel). This disclosure focuses ontransitions between RRC_CONNECTED and RRC_IDLE modes (and analogous NRRRC transitions), not the RRC_CONNECTED states. Accordingly, as usedherein, the terms RRC mode and RRC state are used interchangeably.

In LTE RRC_IDLE state, a UE is known to the core network (CN or EPC),and has an Internet Protocol (IP) address, but is not known/tracked bythe Radio Access Network (E-UTRAN/eNB). The UE can receivebroadcast/multicast data (e.g., System Information, or SI); monitors apaging channel to detect incoming calls; may perform neighbor cellmeasurements; and can do cell (re)selection. A UE in RRC_IDLE may beconfigured by the network for Discontinuous Reception (DRX).

In the LTE RRC_CONNECTED state, the UE is known by the RAN(E-UTRAN/eNB), as well as the core network, and the mobility of the UEis managed by the network. The UE monitors control channels for downlinkdata, sends channel quality feedback, and may request uplink resources.The RRC messages RRCRelease and RRCConnect transition the UE fromRRC_CONNECTED to and from RRC_INACTIVE states.

In LTE Rel-13 a mechanism was introduced for the UE to be suspended bythe network in a suspended state similar to RRC_IDLE but with thedifference that the UE stores the Access Stratum (AS) context or RRCcontext. This makes it possible to reduce the signaling when the UEagain becomes active by resuming the RRC connection, instead of (asprior) to establish the RRC connection from scratch. Reducing thesignaling could have several benefits. First, it would reduce latency,e.g., for smart phones accessing the Internet. Second, the reducedsignaling would reduce battery consumption, which is particularlyimportant for machine type devices sending very little data.

The basis of the Rel-13 solution is that the UE sends anRRCConnectionResumeRequest message to the network, and in responsereceives an RRCConnectionResume from the network. TheRRCConnectionResume is not encrypted but is integrity protected.

As part of the standardized work on 5G NR in 3GPP, it has been decidedthat NR should support an RRC_INACTIVE state with similar properties asthe suspended state in LTE Rel-13. The RRC_INACTIVE has slightlydifferent properties from the LTE Rel-13 suspended state, in that it isa separate RRC state and not part of RRC_IDLE, as in LTE. Additionally,the CN/RAN connection (NG or N2 interface) is kept for RRC_INACTIVEwhile it was suspended in LTE. FIG. 1 depicts the possible RRC statetransitions in NR.

The NR RRC states have the following properties:

-   RRC_IDLE:    -   A UE specific DRX may be configured by upper layers;    -   UE controlled mobility based on network configuration;    -   The UE:        -   Monitors a Paging channel for CN paging using 5G-S-TMSI;    -   Performs neighbouring cell measurements and cell (re-)selection;    -   Acquires system information.-   RRC_INACTIVE:    -   A UE specific DRX may be configured by upper layers or by RRC        layer;    -   UE controlled mobility based on network configuration;    -   The UE stores the AS context;    -   The UE:        -   Monitors a Paging channel for CN paging using 5G-S-TMSI and            RAN paging using I-RNTI;        -   Performs neighbouring cell measurements and cell            (re-)selection;        -   Performs RAN-based notification area updates periodically            and when moving outside the RAN-based notification area;        -   Acquires system information.-   RRC_CONNECTED:    -   The UE stores the AS context.    -   Transfer of unicast data to/from UE.    -   At lower layers, the UE may be configured with a UE specific        DRX.    -   For UEs supporting CA, use of one or more SCells, aggregated        with the SpCell, for increased bandwidth.    -   For UEs supporting DC, use of one SCG, aggregated with the MCG,        for increased bandwidth.    -   Network controlled mobility, i.e. handover within NR and to/from        E-UTRAN.    -   The UE:        -   Monitors a Paging channel;        -   Monitors control channels associated with the shared data            channel to determine if data is scheduled for it;        -   Provides channel quality and feedback information;        -   Performs neighbouring cell measurements and measurement            reporting;        -   Acquires system information.

RRC Resume Procedure in NR and Comparison With LTE

One important aspect of RRC_INACTIVE is the security framework, whichdiffers from the solution in LTE.

In LTE, the UE is suspended and, when attempting to resume, it firstcomputes an integrity security token (called short MAC-I) based on anold security key, and then the UE includes that token in the RRC ResumeRequest. Upon receiving that request, the network fetches the UE contextand sends to the UE an integrity-protected RRC Connection Resume Requestwhich contains a next Hop Chaining Count (NCC) parameter that enablesthe UE to refresh its security keys and start both integrity protectionand encryption.

In NR, differently from LTE, instead of refreshing the keys upon thereception of the RRC Resume message and starting security after that,the NR UE in RRC_INACTIVE receives the NCC in the Suspend message thatinitiates the RRC_INACTIVE state, so that it can refresh the keys evenbefore sending the RRC Resume Request. In NR, it has been agreed thatthe token—equivalent to the short MAC-I in LTE—is computed based on thenewly refreshed keys. Then, the network can fetch the context and sendan RRC Resume message that is not only integrity protected, but alsoencrypted, due to the fact that the UE has already refreshed the keysand initiated security. The agreements related to this procedure weretaken on RAN2#101i in Athens, and are reproduced below:

-   Working assumption:-   1. NCC provided when the connection is suspended.-   2. New key is derived based on the NCC received in the suspend    message and used for the calculation of MAC-I in MSG3.-   Agreements:-   1. Msg3 is protected and verification is performed by the last    serving gNB before UE context is transferred to another network    node.-   FFS: Whether it may also be possible that the target gNB can verify    the Msg3 in some cases. (include in previous offline whether Msg3 is    protected with old key or new)-   2. Msg3 includes a MAC-I in the RRC message as in LTE.-   FFS: Inputs used for MAC-I calculation in order to possibly address    the replay attack concern from SA3.

Below is an excerpt from a draft of 3GPP Technical Standard (TS) 38.331,regarding the Resume procedure in NR RRC, which contains these newsecurity aspects:

-   5.3.13 RRC connection resume-   5.3.13.1 General-   [Figures 5.3.13.1-1 through 5.3.13.1-5 from this specification are    reproduced as drawing FIGS. 2-6]-   The purpose of this procedure is to resume an RRC connection    including resuming SRB(s) and DRB(s) or perform an RNA update.-   5.3.13.2 Initiation-   The UE initiates the procedure when upper layers request resume of    an RRC connection, when responding to NG-RAN paging or upon    triggering RNA updates while the UE is in RRC_INACTIVE.-   Upon initiation of the procedure, the UE shall:    -   Editor's Note: FFS Whether SCG configuration should be released        or whether that should be treated as any other configuration        (i.e. with delta signalling).    -   1>apply the default physical channel configuration as specified        in 9.2.4;    -   1>apply the default semi-persistent scheduling configuration as        specified in 9.2.3;    -   1>apply the default MAC main configuration as specified in        9.2.2;    -   1>apply the CCCH configuration as specified in 9.1.1.2;    -   Editor's Note: FFS Whether NR supports a        timeAlignmentTimerCommon, whether is transmitted in SIB2 and UE        behavior associated).    -   1>start timer T300X;    -   1>stop timer T380;    -   1>initiate transmission of the RRCResumeRequest message in        accordance with 5.3.13.2;    -   Editor's Note: FFS Requirements on up to date system information        acquisition before connection resumption.-   5.3.13.3 Actions related to transmission of RRCResumeRequest message-   The UE shall set the contents of RRCResumeRequest message as    follows:    -   1>set the resumeIdentity to the stored I-RNTI value provided in        suspend;    -   1>set the resumeCause in accordance with the information        received from upper layers or from AS layer;    -   Editor's Note: FFS Whether more aspects related to resumeCause        is needed to be captured (e.g. RNA update due to mobility, RNA        periodic update, etc.).    -   1>restore the RRC configuration and security context from the        stored UE AS context:    -   1>update the K_(gNB) key based on the current K_(gNB) or the NH,        using the stored nextHopChainingCount value, as specified in TS        33.501 [11];    -   Editor's Note: FFS How to handle the case of Reject.    -   1>derive the K_(RRCenc) key, the K_(RRCint), the K_(UPint) key        and the K_(UPenc) key;    -   Editor's Note: FFS Working assumption TBC (NCC in suspend and        new key in RRC Resume Request).    -   1>set the resumeMAC-I to the X least significant bits of the        MAC-I calculated:        -   2>over the ASN.1 encoded as per section 8 (i.e., a multiple            of 8 bits) VarResumeMAC-Input;        -   2>with the K_(RRCint) key and the previously configured            integrity protection algorithm; and        -   2>with all input bits for COUNT, BEARER and DIRECTION set to            binary ones;    -   Editor's Note: FFS Length X of the resumeMAC-I.    -   Editor's Note: FFS Additional input to VarResumeMAC-Input        (replay attacks mitigation).    -   1>restore the PDCP state and re-establish PDCP entities for        SRB1;    -   1>resume SRB1;    -   1>submit the RRCResumeRequest message to lower layers for        transmission;    -   1>configure lower layers to resume integrity protection for all        radio bearers except SRB0 using the previously configured        algorithm and the K_(RRCint) key and K_(UPint) key immediately,        i.e., integrity protection shall be applied to all subsequent        messages received and sent by the UE;        -   NOTE 1: Only DRBs with previously configured UP integrity            protection shall resume integrity protection.    -   1>configure lower layers to resume ciphering for all radio        bearers except SRB0 and to apply the previously configured        ciphering algorithm, the K_(RRCenc) key and the K_(UPenc) key,        i.e. the ciphering configuration shall be applied to all        subsequent messages received and sent by the UE;-   If lower layers indicate an integrity check failure while T300X is    running, perform actions specified in 5.3.13.5.-   The UE shall continue cell re-selection related measurements as well    as cell re-selection evaluation. If the conditions for cell    re-selection are fulfilled, the UE shall perform cell re-selection    as specified in 5.3.13.6.

Agreements on Reject Procedure in NR

The Reject procedure has also been discussed for NR. In RAN2#99bis. Thefollowing has been agreed:

A UE in INACTIVE, trying to resume an RRC connection, can receive MSG4sent over SRB0 (without Integrity protection) to move the UE back intoINACTIVE (i.e. rejected with wait timer).

INACTIVE related parameters/configuration should not be updated by aMSG4 sent over SRB0 (as it is a non-protected message).

FIG. 7 depicts the corresponding signal flow for an RRC_INACTIVE toRRC_INACTIVE transition (rejection scenario).

Current Implementation of Agreements on Reject Procedure to RRC NRSpecifications

As in LTE, timer T302 is started upon the reception of an RRCRejectmessage, which can either be in response to an RRCResumeRequest orRRCSetupRequest, as the following excerpt of 3GPP TS 38.331 shows:

-   5.3.3.x Reception of the RRCReject by the UE-   The UE shall:    -   1>stop timer T300;    -   1>reset MAC and release the MAC configuration;    -   1>start timer T302, with the timer value set to the waitTime;    -   1>inform upper layers about the failure to establish the RRC        connection and access control related information, upon which        the procedure ends;    -   Editor's Note: FFS Which access control related information is        informed to higher layers.

Other Reasons Why Resume Procedure May Not Succeed in NR

There are other cases in which the Resume procedure would fail in NR.These include if the timer, which was started when the UE initiated theResume Procedure, times out; or if the UE receives a packet which failsto pass the integrity check. The current draft specification for thesecases is shown below.

-   5.3.13.5 T300X expiry or Integrity check failure from lower layers    while T300X is running-   The UE shall:    -   1>if timer T300X expires or upon receiving Integrity check        failure indication 2>perform the actions upon going to RRC_IDLE        as specified in 5.3.11 with release cause RRC Resume failure;    -   Editor's Note: It is FFS if T300X is the same as T300.-   5.3.13.y Reception of the RRCReject by the UE-   The UE shall:    -   1>stop timer T300X;    -   1>reset MAC and release the MAC configuration;    -   1>start timer T302, with the timer value set to the waitTime;    -   Editor's Note: FFS Whether RRCReject may include redirection        information and/or frequency/RAT deprioritisation information.    -   1>if RRCReject is sent in response to an RRCResumeRequest        triggered by upper layers;        -   2>inform upper layers about the failure to resume the RRC            connection and access control related information, upon            which the procedure ends;    -   Editor's Note: FFS UE actions if RRCResumeRequest is not        triggered by upper layers.    -   Editor's Note: FFS Additional UE actions upon receiving        RRCReject, e.g. T380 handling, SRB1 suspension, etc.    -   Editor's Note: FFS Which access control related information is        informed to higher layers.

Consideration of the specifications above reveal that the RRC resumeprocedure in NR can fail for various reasons. Two such cases areapparent from the draft specifications above. First, the network rejectsthe Resume Request message. This message is sent on SRB0 withoutsecurity and includes a wait time. The UE will not re-initiate anyresume until the wait time has expired. Second, the UE receives at leasta packet on SRB1 which does not pass integrity verification. In thiscase, the UE will consider that the Resume procedure failed, and reportan error to higher layers.

In addition to these two cases, if the UE performs cell-reselection whena timer (T300X) is running, it will also consider that the resumeprocedure failed, and will either inform upper layers or re-try theresume procedure in the target cell.

A problem with all of these cases is that it is not clear how the UEsecurity context should be handled in case the UE resumes again, after aresume failure. Currently, it is stated that the UE derives a newsecurity context in NR (e.g., new keys) prior to sending the ResumeRequest message. However, if this principle is followed, this would meanthat the UE would yet again derive a new security context when it sendsthe Resume Request again. A problem with that is that the network, e.g.,in case of T300X expiration or cell reselection, may not know the UE hasderived a new security context twice, since it is not certain that thenetwork received the first Resume Request and/or successfully fetchedthe UE context. Also, in the case that the network sent a Rejectmessage, the UE may perform a subsequent Resume in a differentcell/network node, and that network node may not know that the UE haspreviously been rejected—and that it therefore derived the securitycontext multiple times.

The result of the currently specified UE behavior is that the network(security) context and the UE (security) context may not besynchronized. In this case, the subsequent Resume procedure will mostlikely fail since the network will not accept the message from the UE,because it is protected with a security token based on a differentsecurity context that with which the network is operating.

The Background section of this document is provided to place embodimentsof the present invention in technological and operational context, toassist those of skill in the art in understanding their scope andutility. Approaches described in the Background section could bepursued, but are not necessarily approaches that have been previouslyconceived or pursued.

Unless explicitly identified as such, no statement herein is admitted tobe prior art merely by its inclusion in the Background section.

SUMMARY

The following presents a simplified summary of the disclosure in orderto provide a basic understanding to those of skill in the art. Thissummary is not an extensive overview of the disclosure and is notintended to identify key/critical elements of embodiments of theinvention or to delineate the scope of the invention. The sole purposeof this summary is to present some concepts disclosed herein in asimplified form as a prelude to the more detailed description that ispresented later.

According to embodiments of the present invention disclosed and claimedherein, a mechanism is introduced the UE to revert back to an oldsecurity context if the Resume procedure fails. In this way, anysubsequent Resume attempts by the UE will derive new security keys fromthe old keys, which means that the keys and security context will be thesame for each attempt. In this way, the security context in the UE willremain synchronized with the network security context, regardless of howmany attempts the UE has performed (assuming the network does not changethe security context when the Resume procedure fails). Alternatively,the UE may store the new security context it derives during the firstResume attempt, and then ensure that it is reused at subsequent Resumeattempts.

One embodiment relates to a method of updating a security context. Themethod is performed by a wireless device operative in a wirelesscommunication network employing a Radio Resource Control (RRC) protocol.The wireless device in RRC CONNECTED state receives from the network anRRC Suspend message including a security update parameter. In responseto the RRC Suspend message, the wireless device enters an RRC INACTIVEstate and stores a first security context. Upon attempting to transitionto an RRC CONNECTED state, a second security context is generated usingthe security update parameter received in the RRC Suspend message. AnRRC Resume Request message, including a security parameter from thesecond security context, is sent to the network. Only if any of thefollowing events occur, the second security context is discarded and thefirst security context is retrieved: an RRC Reject message is receivedfrom the network in response to the RRC Resume Request message; a timerstarted upon sending the RRC Resume Request message expires withoutreceiving a responsive message from the network; or a cell reselectionis performed prior to receiving a message from the network responsive tothe RRC Resume Request message.

Another embodiment relates to a method of updating a security context.The method is performed by a wireless device operative in a wirelesscommunication network employing a Radio Resource Control (RRC) protocol.The wireless device in RRC CONNECTED state receives from the network anRRC Suspend message including a security update parameter. In responseto the RRC Suspend message, the wireless device enters an RRC INACTIVEstate and stores a first security context. Upon attempting to transitionto an RRC CONNECTED state. A second security context is generated fromthe security update parameter received in the RRC Suspend message. AnRRC Resume Request message, including a security parameter from thesecond security context, is sent to the network. Either immediately inone embodiment, or in another embodiment in response to any of thefollowing events, the second security context is stored and utilizeduntil confirmed by the network: an RRC Reject message is received fromthe network in response to the RRC Resume Request message; a timerstarted upon sending the RRC Resume Request message expires withoutreceiving a responsive message from the network; or a cell reselectionis performed prior to receiving a message from the network responsive tothe RRC Resume Request message.

Yet another embodiment relates to a method of updating a securitycontext for a wireless device. The method is performed by a base stationoperative in a wireless communication network employing a Radio ResourceControl (RRC) protocol. A previously active security context for thewireless device is stored. An RRC Resume Request message including asecurity token is received from the wireless device. A temporarysecurity context for the wireless device is generated. The temporarysecurity context is used to verify the security token. An RRC message issent to the wireless device. If no response to the RRC message isreceived from the wireless device, the temporary security context isdiscarded and the previously active security context is retrieved. Inone embodiment, if a response to the RRC message is received from thewireless device, the temporary security context is made the activesecurity context for the wireless device.

Still another embodiment relates to a wireless device operative in awireless communication network employing an RRC protocol, wherein thewireless device in RRC CONNECTED state receives from the network an RRCSuspend message including a security update parameter, and in responseto the RRC Suspend message enters an RRC INACTIVE state and stores afirst security context. The wireless device includes communicationcircuitry and processing circuitry operatively connected to thecommunication circuitry. The processing circuitry is adapted to, uponattempting to transition to an RRC CONNECTED state, generate a secondsecurity context using the security update parameter received in the RRCSuspend message; send to the network an RRC Resume Request messageincluding a security parameter from the second security context; and inresponse to one of the following events, discard the second securitycontext and retrieve the first security context: receiving from thenetwork an RRC Reject message in response to the RRC Resume Requestmessage; expiration of a timer started upon sending the RRC ResumeRequest message, without receiving a responsive message from thenetwork; or performing a cell reselection prior to receiving a messagefrom the network responsive to the RRC Resume Request message.

Still another embodiment relates to a wireless device operative in awireless communication network employing an RRC protocol. The wirelessdevice in RRC CONNECTED state receives from the network an RRC Suspendmessage including a security update parameter, and in response to theRRC Suspend message enters an RRC INACTIVE state and stores a firstsecurity context. The wireless device includes communication circuitryand processing circuitry operatively connected to the communicationcircuitry. The processing circuitry is adapted to, upon attempting totransition to an RRC CONNECTED state: generate a second security contextfrom the security update parameter received in the RRC Suspend message;send to the network an RRC Resume Request message including a securityparameter from the second security context; and immediately or inresponse to one of the following events, store the second securitycontext and utilize it until confirmed by the network. The eventsinclude receiving from the network an RRC Reject message in response tothe RRC Resume Request message; expiration of a timer started uponsending the RRC Resume Request message, without receiving a responsivemessage from the network; or performing a cell reselection prior toreceiving a message from the network responsive to the RRC ResumeRequest message.

Still another embodiment relates to a base station operative in awireless communication network employing an RRC protocol. The basestation includes communication circuitry and processing circuitryoperatively connected to the communication circuitry. The processingcircuitry is adapted to: store a previously active security context forthe wireless device; receive from the wireless device an RRC ResumeRequest message including a security token; generate a temporarysecurity context for the wireless device; use the temporary securitycontext to verify the security token; send an RRC message to thewireless device; and if no response to the RRC message is received fromthe wireless device, discard the temporary security context and retrievethe previously active security context.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which embodiments of theinvention are shown. However, this invention should not be construed aslimited to the embodiments set forth herein. Rather, these embodimentsare provided so that this disclosure will be thorough and complete, andwill fully convey the scope of the invention to those skilled in theart. Like numbers refer to like elements throughout.

FIG. 1 is a state diagram of RRC states in NR.

FIG. 2 is a signal diagram of an RRC successful connection resumption(3GPP TS 38.331 FIG. 5.3.13.1-1).

FIG. 3 is a signal diagram of an RRC successful connection resumptionvia a connection establishment (FIG. 5.3.13.1-2).

FIG. 4 is a signal diagram of an RRC successful connection resumptionfollowed by a network release (FIG. 5.3.13.1-3).

FIG. 5 is a signal diagram of an RRC successful connection resumptionfollowed by a network release (FIG. 5.3.13.1-4).

FIG. 6 is a signal diagram of a rejected RRC connection resumption (FIG.5.3.13.1-5).

FIG. 7 is a signal diagram of transition from and to RRC_INACTIVE, viaRRCReject.

FIG. 8 is a flow diagram of one method of updating a security context bya wireless device.

FIG. 9 is a flow diagram of another method of updating a securitycontext by a wireless device.

FIG. 10 is a flow diagram of a method of updating a security context fora wireless device by a base station.

FIG. 11 is a hardware block diagram of a wireless device.

FIG. 12 is a functional block diagram of a wireless device according toone embodiment.

FIG. 13 is a functional block diagram of a wireless device according toanother embodiment.

FIG. 14 is a hardware block diagram of a base station.

FIG. 15 is a functional block diagram of a base station.

FIG. 16 is a block diagram of a network and some network components.

FIG. 17 is a block diagram of a User Equipment.

FIG. 18 is a schematic block diagram illustrating a virtualizationenvironment.

FIG. 19 illustrates a telecommunication network connected via anintermediate network to a host computer.

FIG. 20 illustrates host computer communicating via a base station witha user equipment over a partially wireless connection.

FIG. 21 is a flowchart illustrating a host computer communicating with aUE in a communication system.

FIG. 22 is a flowchart illustrating a host computer communicating with aUE in a communication system.

FIG. 23 is a flowchart illustrating a UE communicating with a hostcomputer in a communication system.

FIG. 24 is a flowchart illustrating communication between a base stationand a host computer in a communication system.

DETAILED DESCRIPTION

For simplicity and illustrative purposes, the present invention isdescribed by referring mainly to an exemplary embodiment thereof. In thefollowing description, numerous specific details are set forth in orderto provide a thorough understanding of the present invention. However,it will be readily apparent to one of ordinary skill in the art that thepresent invention may be practiced without limitation to these specificdetails. In this description, well known methods and structures have notbeen described in detail so as not to unnecessarily obscure the presentinvention.

Embodiments Where UE Discards New Security Context

According to one embodiment of the present invention, a UE reverts toits prior security context upon a failed Resume procedure. When the UEgenerates a new security context including new keys (K_(gNB), S-K_(gNB),K_(RRCenc), K_(RRCint), K_(UPint), K_(UPenc), etc.) or applies newparameters (including reset counters) such as NCC, COUNT, etc., it willconsider the new context and parameters as temporary, meaning it willstore old values of the parameters. The UE discards the new securitycontext and restores the stored security context and parameters in thefollowing three cases.

First, the UE restores a prior security context and parameters when itreceives an RRCReject message (or equivalent) in response to the UEresuming a connection (i.e., sending an RRCResumeRequest message). TheRRCReject message could contain a wait time, to which the UE sets atimer, e.g., T302 (although of course any name may be used to denote thetimer). The UE may also obtain the wait time from other sources, e.g.,it may use a pre-defined default value defined in the technicalstandards, or it may receive the wait time in another message, such as abroadcast message.

Second, assuming the UE started a timer, e.g., T300X (although of courseany name may be used to denote the timer) when initiating a Resumeprocedure, then when the timer expires, the UE restores a prior (stored)security context and parameters.

Third, the UE restores a prior security context and parameters when itperforms a cell reselection after requesting a connection (i.e., sendingan RRCResumeRequest message), but prior to receiving a Resume message.Note that if a timer, e.g., T300X (although of course any name may beused to denote the timer) was started when initiating the Resumeprocedure, the UE would revert to a prior security context andparameters upon the cell reselection and while the timer (e.g., T300X)is running

In any of these cases, when the UE performs a subsequent resumeprocedure (i.e., sending an RRCResumeRequest message), e.g., due to theResume request being rejected, a relevant timer expires (e.g., T300X orT380), or it entered another cell, the UE restores the prior, storedsecurity context and parameters, and uses the restored security contextto derive a new security context (e.g., keys).

When the UE receives an RRC Resume or RRC Suspend or RRC Release messagewhich is integrity protected by PDCP layer using the new securitycontext, the UE considers the new security context valid (i.e., nolonger a temporary context), and discards the stored old securitycontext and parameters.

When the UE receives an RRC Setup message, which triggers the UE todiscard its stored AS context, the UE also discards any stored securitycontext (both old and new temporary).

Embodiments Where UE Discards New Security Context

According to another embodiment of the present invention, a UE stores anew security context upon a failed Resume procedure, and reuses it whenagain attempting to Resume. The UE generates a new security contextincluding new keys (K_(gNB), S-K_(gNB), K_(RRCenc), K_(RRCint),K_(UPint), K_(UPenc), etc.) or applies new parameters (including resetcounters) such as NCC, or COUNT. The UE then stores this new securitycontext, for possible use at a later time. The UE stores the newsecurity context (or maintains a stored, new security context) in thefollowing three cases.

First, the UE maintains a new security context and parameters when itreceives an RRCReject message (or equivalent) in response to the UEresuming a connection (i.e., sending an RRCResumeRequest message). TheRRCReject message could contain a wait time, to which the UE sets atimer, e.g., T380 (although of course any name may be used to denote thetimer). The UE may also obtain the wait time from other sources, e.g.,it may use a pre-defined default value defined in the technicalstandards, or it may receive the wait time in another message, such as abroadcast message.

Second, assuming the UE started a timer, e.g., T300X (although of courseany name may be used to denote the timer) when initiating a Resumeprocedure, then when the timer expires, the UE uses the same (stored)new security context and parameters.

Third, the UE maintains a new security context and parameters when itperforms a cell reselection after requesting a connection (i.e., sendingan RRCResumeRequest message), but prior to receiving a Resume message.Note that if a timer, e.g., T300X (although of course any name may beused to denote the timer) was started when initiating the Resumeprocedure, the UE would use the new (stored) security context andparameters upon the cell reselection and while the timer (e.g., T300X)is running.

In any of these cases, when the UE performs a subsequent resumeprocedure (i.e., sending an RRCResumeRequest message), e.g., due to theResume request being rejected, a relevant timer expires (e.g., T300X orT380), or it entered another cell, the UE does not generate a newsecurity context; instead, uses the stored new security context (e.g.keys).

When the UE receives an RRC Resume or RRC Suspend or RRC Release messagewhich is integrity protected by PDCP layer using the new securitycontext, the UE considers the new security context valid.

When the UE receives an RRC Setup message, which triggers the UE todiscard its stored AS context, the UE also discards any stored securitycontext.

Network Embodiments

In either of the above embodiments (upon a failed Resume procedure, theUE either discards new security context and restores the old, or storesand maintains the new security context), the network operatescooperatively.

Upon receiving the UE RRC Resume Request message, the network generatesa new UE security context (e.g., in the source or target RAN node, oranother network node). The new security context (e.g., keys) is used toverify the security token included in the RRCResumeRequest message. Itmay also be used to encrypt and/or integrity protect the RRCResumemessage. When doing this, however, the network considers the securitycontext as a temporary context, and stores the old security context. Ifthe network does not receive any response to a subsequent message thatthe network sends to the UE—e.g., RRC Resume, RRC Suspend, RRCRelease—it either discards the new security context and restores the oldsecurity context and parameters.

Representative Specification Changes

The following are representative examples of changes to the relevant3GPP technical specifications that implement embodiments describedherein. Changes are marked-up (additions):

Embodiments Where UE Discards New Security Context

-   5.3.13.3 Actions related to transmission of RRCResumeRequest message-   The UE shall set the contents of RRCResumeRequest message as    follows:    -   1>set the resumeIdentity to the stored I-RNTI value provided in        suspend;    -   1>set the resumeCause in accordance with the information        received from upper layers or from AS layer;    -   Editor's Note: FFS Whether more aspects related to resumeCause        is needed to be captured (e.g. RNA update due to mobility, RNA        periodic update, etc.).    -   1>restore the RRC configuration and security context from the        stored UE AS context:    -   1>generate a temporary K_(gNB) key based on the current K_(gNB)        or the NH, using the stored nextHopChainingCount value, as        specified in TS 33.501 [11];    -   Editor's Note: FFS How to handle the case of Reject.    -   1>derive the temporary K_(RRCenc) key, the temporary K_(RRCint),        the temporary K_(UPint) key and the temporary K_(UPenc) key;    -   Editor's Note: FFS Working assumption TBC (NCC in suspend and        new key in RRC Resume Request).    -   1>set the resumeMAC-I to the X least significant bits of the        MAC-I calculated:        -   2>over the ASN.1 encoded as per section 8 (i.e., a multiple            of 8 bits) VarResumeMAC-Input;        -   2>with the temporary K_(RRCint) key and the previously            configured integrity protection algorithm; and        -   2>with all input bits for COUNT, BEARER and DIRECTION set to            binary ones;    -   Editor's Note: FFS Length X of the resumeMAC-I.    -   Editor's Note: FFS Additional input to VarResumeMAC-Input        (replay attacks mitigation).    -   1>restore the PDCP state and re-establish PDCP entities for        SRB1;    -   1>resume SRB1;    -   1>submit the RRCResumeRequest message to lower layers for        transmission;    -   1>configure lower layers to resume integrity protection for all        radio bearers except SRB0 using the previously configured        algorithm and the temporary K_(RRCint) key and temporary        K_(UPint) key immediately, i.e., integrity protection shall be        applied to all subsequent messages received and sent by the UE;        -   NOTE 1: Only DRBs with previously configured UP integrity            protection shall resume integrity protection.    -   1>configure lower layers to resume ciphering for all radio        bearers except SRB0 and to apply the previously configured        ciphering algorithm, the temporary K_(RRCenc) key and the        temporary K_(UPenc) key, i.e. the ciphering configuration shall        be applied to all subsequent messages received and sent by the        UE;-   If lower layers indicate an integrity check failure while T300X is    running, perform actions specified in 5.3.13.5.-   The UE shall continue cell re-selection related measurements as well    as cell re-selection evaluation. If the conditions for cell    re-selection are fulfilled, the UE shall perform cell re-selection    as specified in 5.3.3.5.-   5.3.13.5 T300X expiry or Integrity check failure from lower layers    while T300X is running or the UE performs cell reselection while    T300X is running-   The UE shall:    -   1>discard the temporary security context including temporary        keys K_(gNB), K_(RRCint), K_(RRCenc), K_(UPint) and K_(UPenc)    -   1>if timer T300X expires or upon receiving Integrity check        failure indication        -   2>perform the actions upon going to RRC_IDLE as specified in            5.3.11 with release cause RRC Resume failure;    -   Editor's Note: It is FFS if T300X is the same as T300.-   5.3.13.y Reception of the RRCReject by the UE-   The UE shall:    -   1>discard the temporary security context including temporary        keys K_(gNB), K_(RRCint), K_(RRCenc), K_(UPint) and K_(UPenc)    -   1>stop timer T300X;    -   1>reset MAC and release the MAC configuration;    -   1>start timer T302, with the timer value set to the waitTime;        Editor's Note: FFS Whether RRCReject may include redirection        information and/or frequency/RAT deprioritisation information.    -   1>if RRCReject is sent in response to an RRCResumeRequest        triggered by upper layers;        -   2>inform upper layers about the failure to resume the RRC            connection and access control related information, upon            which the procedure ends;    -   Editor's Note: FFS UE actions if RRCResumeRequest is not        triggered by upper layers.    -   Editor's Note: FFS Additional UE actions upon receiving        RRCReject e.g. T380 handling, SRB1 suspension, etc.    -   Editor's Note: FFS Which access control related information is        informed to higher layers.

Embodiments Where UE Retains the New Security Context and Discards theOld

-   5.3.13.3 Actions related to transmission of RRCResumeRequest message-   The UE shall set the contents of RRCResumeRequest message as    follows:    -   1>set the resumeIdentity to the stored I-RNTI value provided in        suspend;    -   1>set the resumeCause in accordance with the information        received from upper layers or from AS layer;    -   Editor's Note: FFS Whether more aspects related to resumeCause        is needed to be captured (e.g. RNA update due to mobility, RNA        periodic update, etc.).    -   1>restore the RRC configuration:    -   1>if the UE has no stored “resume security context”        -   2>restore the security context from the stored UE AS context        -   2>update the K_(g)NB key based on the current K_(g)NB or the            NH, using the stored nextHopChainingCount value, as            specified in TS 33.501 [11];    -   Editor's Note: FFS How to handle the case of Reject.        -   2>derive the K_(RRCenc) key, the K_(RRCint), the K_(UPint)            key and the K_(UPenc) key;    -   Editor's Note: FFS Working assumption TBC (NCC in suspend and        new key in RRC Resume Request).    -   1>else    -   2>set the K_(gNB), the K_(RRCenc) key, the K_(RRCint), the        K_(UPint) key and the K_(UPenc) key to the values in the stored        “resume security context”    -   1>(alternative 1) store the keys K_(gNB), K_(RRCint),        K_(RRCenc), K_(UPint) and K_(UPenc) in the “resume security        context”    -   1>set the resumeMAC-I to the X least significant bits of the        MAC-I calculated:        -   2>over the ASN.1 encoded as per section 8 (i.e., a multiple            of 8 bits) VarResumeMAC-Input;        -   2>with the temporary K_(RRCint) key and the previously            configured integrity protection algorithm; and        -   2>with all input bits for COUNT, BEARER and DIRECTION set to            binary ones;    -   Editor's Note: FFS Length X of the resumeMAC-I.    -   Editor's Note: FFS Additional input to VarResumeMAC-Input        (replay attacks mitigation).    -   1>restore the PDCP state and re-establish PDCP entities for        SRB1;    -   1>resume SRB1;    -   1>submit the RRCResumeRequest message to lower layers for        transmission;    -   1>configure lower layers to resume integrity protection for all        radio bearers except SRB0 using the previously configured        algorithm and the K_(RRCint) key and K_(UPint) key immediately,        i.e., integrity protection shall be applied to all subsequent        messages received and sent by the UE;        -   NOTE 1: Only DRBs with previously configured UP integrity            protection shall resume integrity protection.    -   1>configure lower layers to resume ciphering for all radio        bearers except SRB0 and to apply the previously configured        ciphering algorithm, the K_(RRCenc) key and the K_(UPenc) key,        i.e. the ciphering configuration shall be applied to all        subsequent messages received and sent by the UE; If lower layers        indicate an integrity check failure while T300X is running,        perform actions specified in 5.3.13.5.-   The UE shall continue cell re-selection related measurements as well    as cell re-selection evaluation. If the conditions for cell    re-selection are fulfilled, the UE shall perform cell re-selection    as specified in 5.3.3.5.-   5.3.13.5 T300X expiry or Integrity check failure from lower layers    while T300X is running or the UE performs cell reselection while    T300X is running.-   The UE shall:    -   1>(alternative 2) store the keys K_(gNB), K_(RRCint),        K_(RRCenc), K_(UPint) and K_(UPenc) in the “resume security        context”    -   1>if timer T300X expires or upon receiving Integrity check        failure indication        -   2>perform the actions upon going to RRC_IDLE as specified in            5.3.11 with release cause RRC Resume failure;    -   Editor's Note: It is FFS if T300X is the same as T300.-   5.3.13.y Reception of the RRCReject by the UE-   The UE shall:    -   1>(alternative 2) store the keys K_(gNB), K_(RRCint),        K_(RRCenc), K_(UPint) and K_(UPenc) in the “resume security        context”    -   1>stop timer T300X;    -   1>reset MAC and release the MAC configuration;    -   1>start timer T302, with the timer value set to the waitTime;    -   Editor's Note: FFS Whether RRCReject may include redirection        information and/or frequency/RAT deprioritisation information.    -   1>if RRCReject is sent in response to an RRCResumeRequest        triggered by upper layers;        -   2>inform upper layers about the failure to resume the RRC            connection and access control related information, upon            which the procedure ends;    -   Editor's Note: FFS UE actions if RRCResumeRequest is not        triggered by upper layers.    -   Editor's Note: FFS Additional UE actions upon receiving        RRCReject e.g. T380 handling, SRB1 suspension, etc.    -   Editor's Note: FFS Which access control related information is        informed to higher layers.

Methods

FIG. 8 depicts a method 100 of updating a security context in accordancewith particular embodiments. The method is performed by a wirelessdevice operative in a wireless communication network employing a RadioResource Control (RRC) protocol. The wireless device in RRC CONNECTEDstate receives from the network an RRC Suspend message including asecurity update parameter. In response to the RRC Suspend message, thewireless device enters an RRC INACTIVE state and stores a first securitycontext. Upon attempting to transition to an RRC CONNECTED state, asecond security context is generated using the security update parameterreceived in the RRC Suspend message (block 102). An RRC Resume Requestmessage, including a security parameter from the second securitycontext, is sent to the network (block 104). Only if any of thefollowing events occur, does the method 100 proceed to block 112: an RRCReject message is received from the network in response to the RRCResume Request message (block 106); a timer started upon sending the RRCResume Request message expires without receiving a responsive messagefrom the network (block 108); or a cell reselection is performed priorto receiving a message from the network responsive to the RRC ResumeRequest message (block 110). If the event of any of blocks 106, 108, or110 occur, then in response, the second security context is discardedand the first security context is retrieved (block 112), and the method100 is repeated.

FIG. 9 depicts a method 200 of updating a security context in accordancewith other particular embodiments. The method is performed by a wirelessdevice operative in a wireless communication network employing a RadioResource Control (RRC) protocol. The wireless device in RRC CONNECTEDstate receives from the network an RRC Suspend message including asecurity update parameter. In response to the RRC Suspend message, thewireless device enters an RRC INACTIVE state and stores a first securitycontext. Upon attempting to transition to an RRC CONNECTED state. Asecond security context is generated from the security update parameterreceived in the RRC Suspend message (block 202). An RRC Resume Requestmessage, including a security parameter from the second securitycontext, is sent to the network (block 204). Either immediately in oneembodiment (as indicated by dashed lines), or in another embodiment inresponse to any of the following events, the method 200 proceeds toblock 212: an RRC Reject message is received from the network inresponse to the RRC Resume Request message (block 206); a timer startedupon sending the RRC Resume Request message expires without receiving aresponsive message from the network (block 208); or a cell reselectionis performed prior to receiving a message from the network responsive tothe RRC Resume Request message (block 210) Immediately after block 204in one embodiment (as indicated by dashed lines), or in anotherembodiment if the events of any of blocks 206, 208, or 210 occur, thenin response, the second security context is stored and utilized untilconfirmed by the network (block 212), and the method 200 is repeated,except for block 202.

FIG. 10 depicts a method 300 of updating a security context for awireless device in accordance with particular embodiments. The method isperformed by a base station operative in a wireless communicationnetwork employing a Radio Resource Control (RRC) protocol. A previouslyactive security context for the wireless device is stored (block 302).An RRC Resume Request message including a security token is receivedfrom the wireless device (block 304). A temporary security context forthe wireless device is generated (block 306). The temporary securitycontext is used to verify the security token (block 308). An RRC messageis sent to the wireless device (block 310). If no response to the RRCmessage is received from the wireless device (block 312), the temporarysecurity context is discarded and the previously active security contextis retrieved (block 314). In one embodiment, if a response to the RRCmessage is received from the wireless device (block 312), the temporarysecurity context is made the active security context for the wirelessdevice (block 316).

Apparatuses

Apparatuses described herein may perform the methods 100, 200, 300herein and any other processing by implementing any functional means,modules, units, or circuitry. In one embodiment, for example, theapparatuses comprise respective circuits or circuitry configured toperform the steps shown in the method figures. The circuits or circuitryin this regard may comprise circuits dedicated to performing certainfunctional processing and/or one or more microprocessors in conjunctionwith memory. For instance, the circuitry may include one or moremicroprocessor or microcontrollers, as well as other digital hardware,which may include digital signal processors (DSPs), special-purposedigital logic, and the like. The processing circuitry may be configuredto execute program code stored in memory, which may include one orseveral types of memory such as read-only memory (ROM), random-accessmemory, cache memory, flash memory devices, optical storage devices,etc. Program code stored in memory may include program instructions forexecuting one or more telecommunications and/or data communicationsprotocols as well as instructions for carrying out one or more of thetechniques described herein, in several embodiments. In embodiments thatemploy memory, the memory stores program code that, when executed by theone or more processors, carries out the techniques described herein.

FIG. 11 illustrates a wireless device 10, e.g., in the form of a UE. AUE 10 is any type of device capable of communicating with another radionode, such as a base station or another UE, using radio signals. A UE 10may therefore refer to a machine-to-machine (M2M) device, a machine-typecommunications (MTC) device, a Narrowband Internet of Things (NB IoT)device, etc. The UE 10 may also comprise a cellular telephone or“smartphone,” however, the term UE should be understood to encompass anyradio node 10, even one that does not have a “user.” A UE 10 may also bereferred to as a radio device, a radio communication device, a wirelessdevice, a wireless terminal, or simply a terminal—unless the contextindicates otherwise, the use of any of these terms is intended toinclude device-to-device UEs or devices, machine-type devices, ordevices capable of machine-to-machine communication, sensors equippedwith a wireless device, wireless-enabled table computers, mobileterminals, smart phones, laptop-embedded equipment (LEE), laptop-mountedequipment (LME), USB dongles, wireless customer-premises equipment(CPE), V2X UE, ProSe UE, PDA, iPAD, Tablet, etc. In the discussionherein, the terms machine-to-machine (M2M) device, machine-typecommunication (MTC) device, wireless sensor, and sensor may also beused. It should be understood that these devices, although referred toas UEs 10, may be configured to transmit and/or receive data withoutdirect human interaction.

In some embodiments, the UE 10 includes a user interface, including e.g.a display, touchscreen, keyboard or keypad, microphone, speaker, and thelike) (not shown); in other embodiments, such as in many M2M, MTC, or NBIoT scenarios, the UE 10 may include only a minimal, or no, userinterface. The UE 10 also includes processing circuitry 12; memory 14;and communication circuitry 16, including, e.g., a RF transceiver,connected to one or more antennas 18, to effect wireless communicationacross an air interface to one or more other radio nodes, such as a basestation, access points, and/or other UEs. As indicated by the dashedlines, the antenna(s) 18 may protrude externally from the UE 10, or theantenna(s) 18 may be internal. In some embodiments, a UE 10 mayadditionally include features such as a camera, accelerometer, satellitenavigation signal receiver circuitry, vibrating motor, and the like (notdepicted in FIG. 11).

According to embodiments of the present invention, the memory 14 isoperative to store, and the processing circuitry 12 is operative toexecute, software which when executed is operative to cause the UE 10 toupdate a security context upon exiting an RRC_INACTIVE state. Inparticular, the software, when executed on the processing circuitry 12,is operative to perform the methods 100 and/or 200 described and claimedherein. The processing circuitry 12 in this regard may implement certainfunctional means, units, or modules.

FIG. 12 illustrates a functional block diagram of a wireless device 20in a wireless network according to still other embodiments (for example,the wireless network shown in FIG. 16). As shown, the wireless device 20implements various functional means, units, or modules, e.g., via theprocessing circuitry 12 in FIG. 11 and/or via software code. Thesefunctional means, units, or modules, e.g., for implementing the method100 herein, include for instance: security context generating unit 22,RRC Resume Request sending unit 24, and security context discarding unit26. Security context generating unit 22 is configured to generate asecond security context using a security update parameter received inthe RRC Suspend message. RRC Resume Request sending unit 24 isconfigured to send to the network an RRC Resume Request messageincluding a security parameter from the second security context.Security context discarding unit 26 is configured to, if the wirelessdevice 20 is not transitioned to RRC CONNECTED state, discard the secondsecurity context and retrieve a first security context stored inresponse to receiving an RRC Suspend message and entering an RRCINACTIVE state. The wireless device 20 may not transition to RRCCONNECTED state, for example, for any of the following events occurring:receiving from the network an RRC Reject message in response to the RRCResume Request message; expiration of a timer started upon sending theRRC Resume Request message, without receiving a responsive message fromthe network; or performing a cell reselection prior to receiving amessage from the network responsive to the RRC Resume Request message.

FIG. 13 illustrates a functional block diagram of a wireless device 30in a wireless network according to still other embodiments (for example,the wireless network shown in FIG. 16). As shown, the wireless device 30implements various functional means, units, or modules, e.g., via theprocessing circuitry 12 in FIG. 11 and/or via software code. Thesefunctional means, units, or modules, e.g., for implementing the method200 herein, include for instance: security context generating unit 32,RRC Resume Request sending unit 34, and security context storing unit36. Security context generating unit 32 is configured to generate asecond security context using a security update parameter received inthe RRC Suspend message. RRC Resume Request sending unit 34 isconfigured to send to the network an RRC Resume Request messageincluding a security parameter from the second security context.Security context storing unit 36 is configured to, immediately in oneembodiment, and in another embodiment if the wireless device 30 is nottransitioned to RRC CONNECTED state, store the second security contextand utilize it until confirmed by the network. The wireless device 30may not transition to RRC CONNECTED state, for example, for any of thefollowing events occurring: receiving from the network an RRC Rejectmessage in response to the RRC Resume Request message; expiration of atimer started upon sending the RRC Resume Request message, withoutreceiving a responsive message from the network; or performing a cellreselection prior to receiving a message from the network responsive tothe RRC Resume Request message.

FIG. 14 illustrates a network node 40 as implemented in accordance withone or more embodiments. As shown, the network node 40 includesprocessing circuitry 42 and communication circuitry 46. Thecommunication circuitry 46 is configured to transmit and/or receiveinformation to and/or from one or more other nodes, e.g., via anycommunication technology. The processing circuitry 42 is configured toperform processing described above, such as by executing instructionsstored in memory 44. The processing circuitry 42 in this regard mayimplement certain functional means, units, or modules.

FIG. 14 illustrates a network node 40 in the form of a serving node ofone or more UEs 10, known in the art as a base station, NodeB, NB, eNB,gNB, Radio Base Station, Base Transceiver Station, Access Point, or thelike. The base station 40 includes processing circuitry 42; memory 44;and communication circuitry 46, including e.g. a RF transceiver,connected to one or more antennas 48, to effect wireless communicationacross an air interface to one or more UEs 10. As indicated by thebroken connection to the antenna(s) 48, the antenna(s) 48 may bephysically located separately from the base station 40, such as mountedon a tower, building, or the like. Although the memory 44 is depicted asbeing internal to the processing circuitry 42, those of skill in the artunderstand that the memory 44 may also be external. Those of skill inthe art additionally understand that virtualization techniques allowsome functions nominally executed by the processing circuitry 42 toactually be executed by other hardware, perhaps remotely located (e.g.,in the so-called “cloud”).

According to embodiments of the present invention, the processingcircuitry 42 is operative to cause the base station 40 to updating asecurity context for a wireless device 10. In particular, the processingcircuitry 42 is operative to perform the method 300 described andclaimed herein. The processing circuitry 42 in this regard may implementcertain functional means, units, or modules.

FIG. 15 illustrates a functional block diagram of a base station 50 in awireless network according to still other embodiments (for example, thewireless network shown in FIG. 16). As shown, the network node 50implements various functional means, units, or modules, e.g., via theprocessing circuitry 42 in FIG. 14 and/or via software code. Thesefunctional means, units, or modules, e.g., for implementing the method300 herein, include for instance: security context storing unit 52, RRCmessage receiving unit 54, security context generating unit 56, securitytoken verifying unit 58, RRC message sending unit 60, and securitycontext discarding unit 62. Security context storing unit 52 isconfigured to store a previously active security context for thewireless device. RRC message receiving unit 54 is configured to receivefrom the wireless device an RRC Resume Request message including asecurity token. Security context generating unit 56 is configured togenerate a temporary security context for the wireless device. Securitytoken verifying unit 58 is configured to use the temporary securitycontext to verify the security token. RRC message sending unit 60 isconfigured to send an RRC message to the wireless device. Securitycontext discarding unit 62 is configured to, if the RRC messagereceiving unit 54 indicates that no response to the RRC message isreceived from the wireless device, discard the temporary securitycontext and retrieve the previously active security context.

Those skilled in the art will also appreciate that embodiments hereinfurther include corresponding computer programs.

A computer program comprises instructions which, when executed on atleast one processor of an apparatus, cause the apparatus to carry outany of the respective processing described above. A computer program inthis regard may comprise one or more code modules corresponding to themeans or units described above.

Embodiments further include a carrier containing such a computerprogram. This carrier may comprise one of an electronic signal, opticalsignal, radio signal, or computer readable storage medium.

In this regard, embodiments herein also include a computer programproduct stored on a non-transitory computer readable (storage orrecording) medium and comprising instructions that, when executed by aprocessor of an apparatus, cause the apparatus to perform as describedabove.

Embodiments further include a computer program product comprisingprogram code portions for performing the steps of any of the embodimentsherein when the computer program product is executed by a computingdevice. This computer program product may be stored on a computerreadable recording medium.

Advantages of Embodiments of the Present Invention

Embodiments of the present invention present numerous advantages overthe prior art. For example, the network does not need to have mechanismto keep track of how many failed Resume attempts the UE has performed.This is particularly beneficial when the network is overloaded andrejecting UE resume attempts, in that keeping track of attempts wouldadd to the network load (e.g., increase signaling between basestations).

Embodiments of the present invention also reduce the risk that the UEand network context lose synchronization, which could lead to serviceinterruption for end user traffic, or in the worst case that the UE andnetwork get stuck in an unrecoverable state (e.g., UE keeps resumingagain and again, all leading to failure).

Embodiments of the present invention have been described herein withreference to the RRC_INACTIVE state of NR. However, these embodimentsmay be advantageously applied to other contexts, for example, anyRRC_INACTIVE state (or functional equivalent) in LTE. Furthermore,embodiments are also applicable to Inter-RAT procedures involvingRRC_INACTIVE, such as for example between LTE and NR RATs connected tothe same CN (e.g., a 5G Core Network). One such scenario is when a UE inLTE RRC_CONNECTED is suspended to LTE RRC_INACTIVE, then performsmobility and camps on an NR cell (i.e., becomes in NR RRC_INACTIVE).Another is when a UE in NR RRC_CONNECTED is suspended to NRRRC_INACTIVE, then performs mobility and camps on an LTE cell (i.e.,transit to LTE RRC_INACTIVE).

Over the Top Embodiments

Although the subject matter described herein may be implemented in anyappropriate type of system using any suitable components, theembodiments disclosed herein are described in relation to a wirelessnetwork, such as the example wireless network illustrated in FIG. 16.For simplicity, the wireless network of FIG. 16 only depicts network1606, network nodes 1660 and 1660 b, and WDs 1610, 1610 b, and 1610 c.In practice, a wireless network may further include any additionalelements suitable to support communication between wireless devices orbetween a wireless device and another communication device, such as alandline telephone, a service provider, or any other network node or enddevice. Of the illustrated components, network node 1660 and wirelessdevice (WD) 1610 are depicted with additional detail. The wirelessnetwork may provide communication and other types of services to one ormore wireless devices to facilitate the wireless devices' access toand/or use of the services provided by, or via, the wireless network.

The wireless network may comprise and/or interface with any type ofcommunication, telecommunication, data, cellular, and/or radio networkor other similar type of system. In some embodiments, the wirelessnetwork may be configured to operate according to specific standards orother types of predefined rules or procedures. Thus, particularembodiments of the wireless network may implement communicationstandards, such as Global System for Mobile Communications (GSM),Universal Mobile Telecommunications System (UMTS), Long Term Evolution(LTE), Narrowband Internet of Things (NB-IoT), and/or other suitable 2G,3G, 4G, or 5G standards; wireless local area network (WLAN) standards,such as the IEEE 802.11 standards; and/or any other appropriate wirelesscommunication standard, such as the Worldwide Interoperability forMicrowave Access (WiMax), Bluetooth, Z-Wave and/or ZigBee standards.

Network 1606 may comprise one or more backhaul networks, core networks,IP networks, public switched telephone networks (PSTNs), packet datanetworks, optical networks, wide-area networks (WANs), local areanetworks (LANs), wireless local area networks (WLANs), wired networks,wireless networks, metropolitan area networks, and other networks toenable communication between devices.

Network node 1660 and WD 1610 comprise various components described inmore detail below. These components work together in order to providenetwork node and/or wireless device functionality, such as providingwireless connections in a wireless network. In different embodiments,the wireless network may comprise any number of wired or wirelessnetworks, network nodes, base stations, controllers, wireless devices,relay stations, and/or any other components or systems that mayfacilitate or participate in the communication of data and/or signalswhether via wired or wireless connections.

As used herein, network node refers to equipment capable, configured,arranged and/or operable to communicate directly or indirectly with awireless device and/or with other network nodes or equipment in thewireless network to enable and/or provide wireless access to thewireless device and/or to perform other functions (e.g., administration)in the wireless network. Examples of network nodes include, but are notlimited to, access points (APs) (e.g., radio access points), basestations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs(eNBs) and NR NodeBs (gNBs)). Base stations may be categorized based onthe amount of coverage they provide (or, stated differently, theirtransmit power level) and may then also be referred to as femto basestations, pico base stations, micro base stations, or macro basestations. A base station may be a relay node or a relay donor nodecontrolling a relay. A network node may also include one or more (orall) parts of a distributed radio base station such as centralizeddigital units and/or remote radio units (RRUs), sometimes referred to asRemote Radio Heads (RRHs). Such remote radio units may or may not beintegrated with an antenna as an antenna integrated radio. Parts of adistributed radio base station may also be referred to as nodes in adistributed antenna system (DAS). Yet further examples of network nodesinclude multi-standard radio (MSR) equipment such as MSR BSs, networkcontrollers such as radio network controllers (RNCs) or base stationcontrollers (BSCs), base transceiver stations (BTSs), transmissionpoints, transmission nodes, multi-cell/multicast coordination entities(MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SONnodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As anotherexample, a network node may be a virtual network node as described inmore detail below. More generally, however, network nodes may representany suitable device (or group of devices) capable, configured, arranged,and/or operable to enable and/or provide a wireless device with accessto the wireless network or to provide some service to a wireless devicethat has accessed the wireless network.

In FIG. 16, network node 1660 includes processing circuitry 1670, devicereadable medium 1680, interface 1690, auxiliary equipment 1684, powersource 1686, power circuitry 1687, and antenna 1662. Although networknode 1660 illustrated in the example wireless network of FIG. 16 mayrepresent a device that includes the illustrated combination of hardwarecomponents, other embodiments may comprise network nodes with differentcombinations of components. It is to be understood that a network nodecomprises any suitable combination of hardware and/or software needed toperform the tasks, features, functions and methods disclosed herein.Moreover, while the components of network node 1660 are depicted assingle boxes located within a larger box, or nested within multipleboxes, in practice, a network node may comprise multiple differentphysical components that make up a single illustrated component (e.g.,device readable medium 1680 may comprise multiple separate hard drivesas well as multiple RAM modules).

Similarly, network node 1660 may be composed of multiple physicallyseparate components (e.g., a NodeB component and a RNC component, or aBTS component and a BSC component, etc.), which may each have their ownrespective components. In certain scenarios in which network node 1660comprises multiple separate components (e.g., BTS and BSC components),one or more of the separate components may be shared among severalnetwork nodes. For example, a single RNC may control multiple NodeB's.In such a scenario, each unique NodeB and RNC pair, may in someinstances be considered a single separate network node. In someembodiments, network node 1660 may be configured to support multipleradio access technologies (RATs). In such embodiments, some componentsmay be duplicated (e.g., separate device readable medium 1680 for thedifferent RATs) and some components may be reused (e.g., the sameantenna 1662 may be shared by the RATs). Network node 1660 may alsoinclude multiple sets of the various illustrated components fordifferent wireless technologies integrated into network node 1660, suchas, for example, GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wirelesstechnologies. These wireless technologies may be integrated into thesame or different chip or set of chips and other components withinnetwork node 1660.

Processing circuitry 1670 is configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being provided by a network node. These operationsperformed by processing circuitry 1670 may include processinginformation obtained by processing circuitry 1670 by, for example,converting the obtained information into other information, comparingthe obtained information or converted information to information storedin the network node, and/or performing one or more operations based onthe obtained information or converted information, and as a result ofsaid processing making a determination.

Processing circuitry 1670 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software and/or encoded logicoperable to provide, either alone or in conjunction with other networknode 1660 components, such as device readable medium 1680, network node1660 functionality. For example, processing circuitry 1670 may executeinstructions stored in device readable medium 1680 or in memory withinprocessing circuitry 1670. Such functionality may include providing anyof the various wireless features, functions, or benefits discussedherein. In some embodiments, processing circuitry 1670 may include asystem on a chip (SOC).

In some embodiments, processing circuitry 1670 may include one or moreof radio frequency (RF) transceiver circuitry 1672 and basebandprocessing circuitry 1674. In some embodiments, radio frequency (RF)transceiver circuitry 1672 and baseband processing circuitry 1674 may beon separate chips (or sets of chips), boards, or units, such as radiounits and digital units. In alternative embodiments, part or all of RFtransceiver circuitry 1672 and baseband processing circuitry 1674 may beon the same chip or set of chips, boards, or units

In certain embodiments, some or all of the functionality describedherein as being provided by a network node, base station, eNB or othersuch network device may be performed by processing circuitry 1670executing instructions stored on device readable medium 1680 or memorywithin processing circuitry 1670. In alternative embodiments, some orall of the functionality may be provided by processing circuitry 1670without executing instructions stored on a separate or discrete devicereadable medium, such as in a hard-wired manner In any of thoseembodiments, whether executing instructions stored on a device readablestorage medium or not, processing circuitry 1670 can be configured toperform the described functionality. The benefits provided by suchfunctionality are not limited to processing circuitry 1670 alone or toother components of network node 1660, but are enjoyed by network node1660 as a whole, and/or by end users and the wireless network generally.

Device readable medium 1680 may comprise any form of volatile ornon-volatile computer readable memory including, without limitation,persistent storage, solid-state memory, remotely mounted memory,magnetic media, optical media, random access memory (RAM), read-onlymemory (ROM), mass storage media (for example, a hard disk), removablestorage media (for example, a flash drive, a Compact Disk (CD) or aDigital Video Disk (DVD)), and/or any other volatile or non-volatile,non-transitory device readable and/or computer-executable memory devicesthat store information, data, and/or instructions that may be used byprocessing circuitry 1670. Device readable medium 1680 may store anysuitable instructions, data or information, including a computerprogram, software, an application including one or more of logic, rules,code, tables, etc. and/or other instructions capable of being executedby processing circuitry 1670 and, utilized by network node 1660. Devicereadable medium 1680 may be used to store any calculations made byprocessing circuitry 1670 and/or any data received via interface 1690.In some embodiments, processing circuitry 1670 and device readablemedium 1680 may be considered to be integrated.

Interface 1690 is used in the wired or wireless communication ofsignalling and/or data between network node 1660, network 1606, and/orWDs 1610. As illustrated, interface 1690 comprises port(s)/terminal(s)1694 to send and receive data, for example to and from network 1606 overa wired connection. Interface 1690 also includes radio front endcircuitry 1692 that may be coupled to, or in certain embodiments a partof, antenna 1662. Radio front end circuitry 1692 comprises filters 1698and amplifiers 1696. Radio front end circuitry 1692 may be connected toantenna 1662 and processing circuitry 1670. Radio front end circuitrymay be configured to condition signals communicated between antenna 1662and processing circuitry 1670. Radio front end circuitry 1692 mayreceive digital data that is to be sent out to other network nodes orWDs via a wireless connection. Radio front end circuitry 1692 mayconvert the digital data into a radio signal having the appropriatechannel and bandwidth parameters using a combination of filters 1698and/or amplifiers 1696. The radio signal may then be transmitted viaantenna 1662. Similarly, when receiving data, antenna 1662 may collectradio signals which are then converted into digital data by radio frontend circuitry 1692. The digital data may be passed to processingcircuitry 1670. In other embodiments, the interface may comprisedifferent components and/or different combinations of components.

In certain alternative embodiments, network node 1660 may not includeseparate radio front end circuitry 1692, instead, processing circuitry1670 may comprise radio front end circuitry and may be connected toantenna 1662 without separate radio front end circuitry 1692. Similarly,in some embodiments, all or some of RF transceiver circuitry 1672 may beconsidered a part of interface 1690. In still other embodiments,interface 1690 may include one or more ports or terminals 1694, radiofront end circuitry 1692, and RF transceiver circuitry 1672, as part ofa radio unit (not shown), and interface 1690 may communicate withbaseband processing circuitry 1674, which is part of a digital unit (notshown).

Antenna 1662 may include one or more antennas, or antenna arrays,configured to send and/or receive wireless signals. Antenna 1662 may becoupled to radio front end circuitry 1692 and may be any type of antennacapable of transmitting and receiving data and/or signals wirelessly. Insome embodiments, antenna 1662 may comprise one or moreomni-directional, sector or panel antennas operable to transmit/receiveradio signals between, for example, 2 GHz and 66 GHz. Anomni-directional antenna may be used to transmit/receive radio signalsin any direction, a sector antenna may be used to transmit/receive radiosignals from devices within a particular area, and a panel antenna maybe a line of sight antenna used to transmit/receive radio signals in arelatively straight line. In some instances, the use of more than oneantenna may be referred to as MIMO. In certain embodiments, antenna 1662may be separate from network node 1660 and may be connectable to networknode 1660 through an interface or port.

Antenna 1662, interface 1690, and/or processing circuitry 1670 may beconfigured to perform any receiving operations and/or certain obtainingoperations described herein as being performed by a network node. Anyinformation, data and/or signals may be received from a wireless device,another network node and/or any other network equipment. Similarly,antenna 1662, interface 1690, and/or processing circuitry 1670 may beconfigured to perform any transmitting operations described herein asbeing performed by a network node. Any information, data and/or signalsmay be transmitted to a wireless device, another network node and/or anyother network equipment.

Power circuitry 1687 may comprise, or be coupled to, power managementcircuitry and is configured to supply the components of network node1660 with power for performing the functionality described herein. Powercircuitry 1687 may receive power from power source 1686. Power source1686 and/or power circuitry 1687 may be configured to provide power tothe various components of network node 1660 in a form suitable for therespective components (e.g., at a voltage and current level needed foreach respective component). Power source 1686 may either be included in,or external to, power circuitry 1687 and/or network node 1660. Forexample, network node 1660 may be connectable to an external powersource (e.g., an electricity outlet) via an input circuitry or interfacesuch as an electrical cable, whereby the external power source suppliespower to power circuitry 1687. As a further example, power source 1686may comprise a source of power in the form of a battery or battery packwhich is connected to, or integrated in, power circuitry 1687. Thebattery may provide backup power should the external power source fail.Other types of power sources, such as photovoltaic devices, may also beused.

Alternative embodiments of network node 1660 may include additionalcomponents beyond those shown in FIG. 16 that may be responsible forproviding certain aspects of the network node's functionality, includingany of the functionality described herein and/or any functionalitynecessary to support the subject matter described herein. For example,network node 1660 may include user interface equipment to allow input ofinformation into network node 1660 and to allow output of informationfrom network node 1660. This may allow a user to perform diagnostic,maintenance, repair, and other administrative functions for network node1660.

As used herein, wireless device (WD) refers to a device capable,configured, arranged and/or operable to communicate wirelessly withnetwork nodes and/or other wireless devices. Unless otherwise noted, theterm WD may be used interchangeably herein with user equipment (UE).Communicating wirelessly may involve transmitting and/or receivingwireless signals using electromagnetic waves, radio waves, infraredwaves, and/or other types of signals suitable for conveying informationthrough air. In some embodiments, a WD may be configured to transmitand/or receive information without direct human interaction. Forinstance, a WD may be designed to transmit information to a network on apredetermined schedule, when triggered by an internal or external event,or in response to requests from the network. Examples of a WD include,but are not limited to, a smart phone, a mobile phone, a cell phone, avoice over IP (VoIP) phone, a wireless local loop phone, a desktopcomputer, a personal digital assistant (PDA), a wireless cameras, agaming console or device, a music storage device, a playback appliance,a wearable terminal device, a wireless endpoint, a mobile station, atablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mountedequipment (LME), a smart device, a wireless customer-premise equipment(CPE). a vehicle-mounted wireless terminal device, etc. A WD may supportdevice-to-device (D2D) communication, for example by implementing a 3GPPstandard for sidelink communication, vehicle-to-vehicle (V2V),vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may inthis case be referred to as a D2D communication device. As yet anotherspecific example, in an Internet of Things (IoT) scenario, a WD mayrepresent a machine or other device that performs monitoring and/ormeasurements, and transmits the results of such monitoring and/ormeasurements to another WD and/or a network node. The WD may in thiscase be a machine-to-machine (M2M) device, which may in a 3GPP contextbe referred to as an MTC device. As one particular example, the WD maybe a UE implementing the 3GPP narrow band internet of things (NB-IoT)standard. Particular examples of such machines or devices are sensors,metering devices such as power meters, industrial machinery, or home orpersonal appliances (e.g. refrigerators, televisions, etc.) personalwearables (e.g., watches, fitness trackers, etc.). In other scenarios, aWD may represent a vehicle or other equipment that is capable ofmonitoring and/or reporting on its operational status or other functionsassociated with its operation. A WD as described above may represent theendpoint of a wireless connection, in which case the device may bereferred to as a wireless terminal. Furthermore, a WD as described abovemay be mobile, in which case it may also be referred to as a mobiledevice or a mobile terminal.

As illustrated, wireless device 1610 includes antenna 1611, interface1614, processing circuitry 1620, device readable medium 1630, userinterface equipment 1632, auxiliary equipment 1634, power source 1636and power circuitry 1637. WD 1610 may include multiple sets of one ormore of the illustrated components for different wireless technologiessupported by WD 1610, such as, for example, GSM, WCDMA, LTE, NR, WiFi,WiMAX, NB-IoT, or Bluetooth wireless technologies, just to mention afew. These wireless technologies may be integrated into the same ordifferent chips or set of chips as other components within WD 1610.

Antenna 1611 may include one or more antennas or antenna arrays,configured to send and/or receive wireless signals, and is connected tointerface 1614. In certain alternative embodiments, antenna 1611 may beseparate from WD 1610 and be connectable to WD 1610 through an interfaceor port. Antenna 1611, interface 1614, and/or processing circuitry 1620may be configured to perform any receiving or transmitting operationsdescribed herein as being performed by a WD. Any information, dataand/or signals may be received from a network node and/or another WD. Insome embodiments, radio front end circuitry and/or antenna 1611 may beconsidered an interface.

As illustrated, interface 1614 comprises radio front end circuitry 1612and antenna 1611. Radio front end circuitry 1612 comprise one or morefilters 1618 and amplifiers 1616. Radio front end circuitry 1612 isconnected to antenna 1611 and processing circuitry 1620, and isconfigured to condition signals communicated between antenna 1611 andprocessing circuitry 1620. Radio front end circuitry 1612 may be coupledto or a part of antenna 1611. In some embodiments, WD 1610 may notinclude separate radio front end circuitry 1612; rather, processingcircuitry 1620 may comprise radio front end circuitry and may beconnected to antenna 1611. Similarly, in some embodiments, some or allof RF transceiver circuitry 1622 may be considered a part of interface1614. Radio front end circuitry 1612 may receive digital data that is tobe sent out to other network nodes or WDs via a wireless connection.Radio front end circuitry 1612 may convert the digital data into a radiosignal having the appropriate channel and bandwidth parameters using acombination of filters 1618 and/or amplifiers 1616. The radio signal maythen be transmitted via antenna 1611. Similarly, when receiving data,antenna 1611 may collect radio signals which are then converted intodigital data by radio front end circuitry 1612. The digital data may bepassed to processing circuitry 1620. In other embodiments, the interfacemay comprise different components and/or different combinations ofcomponents.

Processing circuitry 1620 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software, and/or encoded logicoperable to provide, either alone or in conjunction with other WD 1610components, such as device readable medium 1630, WD 1610 functionality.Such functionality may include providing any of the various wirelessfeatures or benefits discussed herein. For example, processing circuitry1620 may execute instructions stored in device readable medium 1630 orin memory within processing circuitry 1620 to provide the functionalitydisclosed herein.

As illustrated, processing circuitry 1620 includes one or more of RFtransceiver circuitry 1622, baseband processing circuitry 1624, andapplication processing circuitry 1626. In other embodiments, theprocessing circuitry may comprise different components and/or differentcombinations of components. In certain embodiments processing circuitry1620 of WD 1610 may comprise a SOC. In some embodiments, RF transceivercircuitry 1622, baseband processing circuitry 1624, and applicationprocessing circuitry 1626 may be on separate chips or sets of chips. Inalternative embodiments, part or all of baseband processing circuitry1624 and application processing circuitry 1626 may be combined into onechip or set of chips, and RF transceiver circuitry 1622 may be on aseparate chip or set of chips. In still alternative embodiments, part orall of RF transceiver circuitry 1622 and baseband processing circuitry1624 may be on the same chip or set of chips, and application processingcircuitry 1626 may be on a separate chip or set of chips. In yet otheralternative embodiments, part or all of RF transceiver circuitry 1622,baseband processing circuitry 1624, and application processing circuitry1626 may be combined in the same chip or set of chips. In someembodiments, RF transceiver circuitry 1622 may be a part of interface1614. RF transceiver circuitry 1622 may condition RF signals forprocessing circuitry 1620.

In certain embodiments, some or all of the functionality describedherein as being performed by a WD may be provided by processingcircuitry 1620 executing instructions stored on device readable medium1630, which in certain embodiments may be a computer-readable storagemedium. In alternative embodiments, some or all of the functionality maybe provided by processing circuitry 1620 without executing instructionsstored on a separate or discrete device readable storage medium, such asin a hard-wired manner In any of those particular embodiments, whetherexecuting instructions stored on a device readable storage medium ornot, processing circuitry 1620 can be configured to perform thedescribed functionality. The benefits provided by such functionality arenot limited to processing circuitry 1620 alone or to other components ofWD 1610, but are enjoyed by WD 1610 as a whole, and/or by end users andthe wireless network generally.

Processing circuitry 1620 may be configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being performed by a WD. These operations, asperformed by processing circuitry 1620, may include processinginformation obtained by processing circuitry 1620 by, for example,converting the obtained information into other information, comparingthe obtained information or converted information to information storedby WD 1610, and/or performing one or more operations based on theobtained information or converted information, and as a result of saidprocessing making a determination.

Device readable medium 1630 may be operable to store a computer program,software, an application including one or more of logic, rules, code,tables, etc. and/or other instructions capable of being executed byprocessing circuitry 1620. Device readable medium 1630 may includecomputer memory (e.g., Random Access Memory (RAM) or Read Only Memory(ROM)), mass storage media (e.g., a hard disk), removable storage media(e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or anyother volatile or non-volatile, non-transitory device readable and/orcomputer executable memory devices that store information, data, and/orinstructions that may be used by processing circuitry 1620. In someembodiments, processing circuitry 1620 and device readable medium 1630may be considered to be integrated.

User interface equipment 1632 may provide components that allow for ahuman user to interact with WD 1610. Such interaction may be of manyforms, such as visual, audial, tactile, etc. User interface equipment1632 may be operable to produce output to the user and to allow the userto provide input to WD 1610. The type of interaction may vary dependingon the type of user interface equipment 1632 installed in WD 1610. Forexample, if WD 1610 is a smart phone, the interaction may be via a touchscreen; if WD 1610 is a smart meter, the interaction may be through ascreen that provides usage (e.g., the number of gallons used) or aspeaker that provides an audible alert (e.g., if smoke is detected).User interface equipment 1632 may include input interfaces, devices andcircuits, and output interfaces, devices and circuits. User interfaceequipment 1632 is configured to allow input of information into WD 1610,and is connected to processing circuitry 1620 to allow processingcircuitry 1620 to process the input information. User interfaceequipment 1632 may include, for example, a microphone, a proximity orother sensor, keys/buttons, a touch display, one or more cameras, a USBport, or other input circuitry. User interface equipment 1632 is alsoconfigured to allow output of information from WD 1610, and to allowprocessing circuitry 1620 to output information from WD 1610. Userinterface equipment 1632 may include, for example, a speaker, a display,vibrating circuitry, a USB port, a headphone interface, or other outputcircuitry. Using one or more input and output interfaces, devices, andcircuits, of user interface equipment 1632, WD 1610 may communicate withend users and/or the wireless network, and allow them to benefit fromthe functionality described herein.

Auxiliary equipment 1634 is operable to provide more specificfunctionality which may not be generally performed by WDs. This maycomprise specialized sensors for doing measurements for variouspurposes, interfaces for additional types of communication such as wiredcommunications etc. The inclusion and type of components of auxiliaryequipment 1634 may vary depending on the embodiment and/or scenario.

Power source 1636 may, in some embodiments, be in the form of a batteryor battery pack. Other types of power sources, such as an external powersource (e.g., an electricity outlet), photovoltaic devices or powercells, may also be used. WD 1610 may further comprise power circuitry1637 for delivering power from power source 1636 to the various parts ofWD 1610 which need power from power source 1636 to carry out anyfunctionality described or indicated herein. Power circuitry 1637 may incertain embodiments comprise power management circuitry. Power circuitry1637 may additionally or alternatively be operable to receive power froman external power source; in which case WD 1610 may be connectable tothe external power source (such as an electricity outlet) via inputcircuitry or an interface such as an electrical power cable. Powercircuitry 1637 may also in certain embodiments be operable to deliverpower from an external power source to power source 1636. This may be,for example, for the charging of power source 1636. Power circuitry 1637may perform any formatting, converting, or other modification to thepower from power source 1636 to make the power suitable for therespective components of WD 1610 to which power is supplied.

FIG. 17 illustrates one embodiment of a UE in accordance with variousaspects described herein. As used herein, a user equipment or UE may notnecessarily have a user in the sense of a human user who owns and/oroperates the relevant device. Instead, a UE may represent a device thatis intended for sale to, or operation by, a human user but which maynot, or which may not initially, be associated with a specific humanuser (e.g., a smart sprinkler controller). Alternatively, a UE mayrepresent a device that is not intended for sale to, or operation by, anend user but which may be associated with or operated for the benefit ofa user (e.g., a smart power meter). UE 17200 may be any UE identified bythe 3rd Generation Partnership Project (3GPP), including a NB-IoT UE, amachine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.UE 1700, as illustrated in FIG. 17, is one example of a WD configuredfor communication in accordance with one or more communication standardspromulgated by the 3rd Generation Partnership Project (3GPP), such as3GPP′s GSM, UMTS, LTE, and/or 5G standards. As mentioned previously, theterm WD and UE may be used interchangeable. Accordingly, although FIG.17 is a UE, the components discussed herein are equally applicable to aWD, and vice-versa.

In FIG. 17, UE 1700 includes processing circuitry 1701 that isoperatively coupled to input/output interface 1705, radio frequency (RF)interface 1709, network connection interface 1711, memory 1715 includingrandom access memory (RAM) 1717, read-only memory (ROM) 1719, andstorage medium 1721 or the like, communication subsystem 1731, powersource 1713, and/or any other component, or any combination thereof.Storage medium 1721 includes operating system 1723, application program1725, and data 1727. In other embodiments, storage medium 1721 mayinclude other similar types of information. Certain UEs may utilize allof the components shown in FIG. 17, or only a subset of the components.The level of integration between the components may vary from one UE toanother UE. Further, certain UEs may contain multiple instances of acomponent, such as multiple processors, memories, transceivers,transmitters, receivers, etc.

In FIG. 17, processing circuitry 1701 may be configured to processcomputer instructions and data. Processing circuitry 1701 may beconfigured to implement any sequential state machine operative toexecute machine instructions stored as machine-readable computerprograms in the memory, such as one or more hardware-implemented statemachines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logictogether with appropriate firmware; one or more stored program,general-purpose processors, such as a microprocessor or Digital SignalProcessor (DSP), together with appropriate software; or any combinationof the above. For example, the processing circuitry 1701 may include twocentral processing units (CPUs). Data may be information in a formsuitable for use by a computer.

In the depicted embodiment, input/output interface 1705 may beconfigured to provide a communication interface to an input device,output device, or input and output device. UE 1700 may be configured touse an output device via input/output interface 1705. An output devicemay use the same type of interface port as an input device. For example,a USB port may be used to provide input to and output from UE 1700. Theoutput device may be a speaker, a sound card, a video card, a display, amonitor, a printer, an actuator, an emitter, a smartcard, another outputdevice, or any combination thereof. UE 1700 may be configured to use aninput device via input/output interface 1705 to allow a user to captureinformation into UE 1700. The input device may include a touch-sensitiveor presence-sensitive display, a camera (e.g., a digital camera, adigital video camera, a web camera, etc.), a microphone, a sensor, amouse, a trackball, a directional pad, a trackpad, a scroll wheel, asmartcard, and the like. The presence-sensitive display may include acapacitive or resistive touch sensor to sense input from a user. Asensor may be, for instance, an accelerometer, a gyroscope, a tiltsensor, a force sensor, a magnetometer, an optical sensor, a proximitysensor, another like sensor, or any combination thereof. For example,the input device may be an accelerometer, a magnetometer, a digitalcamera, a microphone, and an optical sensor.

In FIG. 17, RF interface 1709 may be configured to provide acommunication interface to RF components such as a transmitter, areceiver, and an antenna. Network connection interface 1711 may beconfigured to provide a communication interface to network 1743 a.Network 1743 a may encompass wired and/or wireless networks such as alocal-area network (LAN), a wide-area network (WAN), a computer network,a wireless network, a telecommunications network, another like networkor any combination thereof. For example, network 1743 a may comprise aWi-Fi network. Network connection interface 1711 may be configured toinclude a receiver and a transmitter interface used to communicate withone or more other devices over a communication network according to oneor more communication protocols, such as Ethernet, TCP/IP, SONET, ATM,or the like. Network connection interface 1711 may implement receiverand transmitter functionality appropriate to the communication networklinks (e.g., optical, electrical, and the like). The transmitter andreceiver functions may share circuit components, software or firmware,or alternatively may be implemented separately.

RAM 1717 may be configured to interface via bus 1702 to processingcircuitry 1701 to provide storage or caching of data or computerinstructions during the execution of software programs such as theoperating system, application programs, and device drivers. ROM 1719 maybe configured to provide computer instructions or data to processingcircuitry 1701. For example, ROM 1719 may be configured to storeinvariant low-level system code or data for basic system functions suchas basic input and output (I/O), startup, or reception of keystrokesfrom a keyboard that are stored in a non-volatile memory. Storage medium1721 may be configured to include memory such as RAM, ROM, programmableread-only memory (PROM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), magneticdisks, optical disks, floppy disks, hard disks, removable cartridges, orflash drives. In one example, storage medium 1721 may be configured toinclude operating system 1723, application program 1725 such as a webbrowser application, a widget or gadget engine or another application,and data file 1727. Storage medium 1721 may store, for use by UE 1700,any of a variety of various operating systems or combinations ofoperating systems.

Storage medium 1721 may be configured to include a number of physicaldrive units, such as redundant array of independent disks (RAID), floppydisk drive, flash memory, USB flash drive, external hard disk drive,thumb drive, pen drive, key drive, high-density digital versatile disc(HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray opticaldisc drive, holographic digital data storage (HDDS) optical disc drive,external mini-dual in-line memory module (DIMM), synchronous dynamicrandom access memory (SDRAM), external micro-DIMM SDRAM, smartcardmemory such as a subscriber identity module or a removable user identity(SIM/RUIM) module, other memory, or any combination thereof. Storagemedium 1721 may allow UE 1700 to access computer-executableinstructions, application programs or the like, stored on transitory ornon-transitory memory media, to off-load data, or to upload data. Anarticle of manufacture, such as one utilizing a communication system maybe tangibly embodied in storage medium 1721, which may comprise a devicereadable medium.

In FIG. 17, processing circuitry 1701 may be configured to communicatewith network 1743 b using communication subsystem 1731. Network 1743 aand network 1743 b may be the same network or networks or differentnetwork or networks. Communication subsystem 1731 may be configured toinclude one or more transceivers used to communicate with network 1743b. For example, communication subsystem 1731 may be configured toinclude one or more transceivers used to communicate with one or moreremote transceivers of another device capable of wireless communicationsuch as another WD, UE, or base station of a radio access network (RAN)according to one or more communication protocols, such as IEEE 802.17,CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver mayinclude transmitter 1733 and/or receiver 1735 to implement transmitteror receiver functionality, respectively, appropriate to the RAN links(e.g., frequency allocations and the like). Further, transmitter 1733and receiver 1735 of each transceiver may share circuit components,software or firmware, or alternatively may be implemented separately.

In the illustrated embodiment, the communication functions ofcommunication subsystem 1731 may include data communication, voicecommunication, multimedia communication, short-range communications suchas Bluetooth, near-field communication, location-based communicationsuch as the use of the global positioning system (GPS) to determine alocation, another like communication function, or any combinationthereof. For example, communication subsystem 1731 may include cellularcommunication, Wi-Fi communication, Bluetooth communication, and GPScommunication. Network 1743 b may encompass wired and/or wirelessnetworks such as a local-area network (LAN), a wide-area network (WAN),a computer network, a wireless network, a telecommunications network,another like network or any combination thereof. For example, network1743 b may be a cellular network, a Wi-Fi network, and/or a near-fieldnetwork. Power source 1713 may be configured to provide alternatingcurrent (AC) or direct current (DC) power to components of UE 1700.

The features, benefits and/or functions described herein may beimplemented in one of the components of UE 1700 or partitioned acrossmultiple components of UE 1700. Further, the features, benefits, and/orfunctions described herein may be implemented in any combination ofhardware, software or firmware. In one example, communication subsystem1731 may be configured to include any of the components describedherein. Further, processing circuitry 1701 may be configured tocommunicate with any of such components over bus 1702. In anotherexample, any of such components may be represented by programinstructions stored in memory that when executed by processing circuitry1701 perform the corresponding functions described herein. In anotherexample, the functionality of any of such components may be partitionedbetween processing circuitry 1701 and communication subsystem 1731. Inanother example, the non-computationally intensive functions of any ofsuch components may be implemented in software or firmware and thecomputationally intensive functions may be implemented in hardware.

FIG. 18 is a schematic block diagram illustrating a virtualizationenvironment 1800 in which functions implemented by some embodiments maybe virtualized. In the present context, virtualizing means creatingvirtual versions of apparatuses or devices which may includevirtualizing hardware platforms, storage devices and networkingresources. As used herein, virtualization can be applied to a node(e.g., a virtualized base station or a virtualized radio access node) orto a device (e.g., a UE, a wireless device or any other type ofcommunication device) or components thereof and relates to animplementation in which at least a portion of the functionality isimplemented as one or more virtual components (e.g., via one or moreapplications, components, functions, virtual machines or containersexecuting on one or more physical processing nodes in one or morenetworks).

In some embodiments, some or all of the functions described herein maybe implemented as virtual components executed by one or more virtualmachines implemented in one or more virtual environments 1800 hosted byone or more of hardware nodes 1830. Further, in embodiments in which thevirtual node is not a radio access node or does not require radioconnectivity (e.g., a core network node), then the network node may beentirely virtualized.

The functions may be implemented by one or more applications 1820 (whichmay alternatively be called software instances, virtual appliances,network functions, virtual nodes, virtual network functions, etc.)operative to implement some of the features, functions, and/or benefitsof some of the embodiments disclosed herein. Applications 1820 are runin virtualization environment 1800 which provides hardware 1830comprising processing circuitry 1860 and memory 1890. Memory 1890contains instructions 1895 executable by processing circuitry 1860whereby application 1820 is operative to provide one or more of thefeatures, benefits, and/or functions disclosed herein.

Virtualization environment 1800, comprises general-purpose orspecial-purpose network hardware devices 1830 comprising a set of one ormore processors or processing circuitry 1860, which may be commercialoff-the-shelf (COTS) processors, dedicated Application SpecificIntegrated Circuits (ASICs), or any other type of processing circuitryincluding digital or analog hardware components or special purposeprocessors. Each hardware device may comprise memory 1890-1 which may benon-persistent memory for temporarily storing instructions 1895 orsoftware executed by processing circuitry 1860. Each hardware device maycomprise one or more network interface controllers (NICs) 1870, alsoknown as network interface cards, which include physical networkinterface 1880. Each hardware device may also include non-transitory,persistent, machine-readable storage media 1890-2 having stored thereinsoftware 1895 and/or instructions executable by processing circuitry1860. Software 1895 may include any type of software including softwarefor instantiating one or more virtualization layers 1850 (also referredto as hypervisors), software to execute virtual machines 1840 as well assoftware allowing it to execute functions, features and/or benefitsdescribed in relation with some embodiments described herein.

Virtual machines 1840, comprise virtual processing, virtual memory,virtual networking or interface and virtual storage, and may be run by acorresponding virtualization layer 1850 or hypervisor. Differentembodiments of the instance of virtual appliance 1820 may be implementedon one or more of virtual machines 1840, and the implementations may bemade in different ways.

During operation, processing circuitry 1860 executes software 1895 toinstantiate the hypervisor or virtualization layer 1850, which maysometimes be referred to as a virtual machine monitor (VMM).Virtualization layer 1850 may present a virtual operating platform thatappears like networking hardware to virtual machine 1840.

As shown in FIG. 18, hardware 1830 may be a standalone network node withgeneric or specific components. Hardware 1830 may comprise antenna 18225and may implement some functions via virtualization. Alternatively,hardware 1830 may be part of a larger cluster of hardware (e.g. such asin a data center or customer premise equipment (CPE)) where manyhardware nodes work together and are managed via management andorchestration (MANO) 18100, which, among others, oversees lifecyclemanagement of applications 1820.

Virtualization of the hardware is in some contexts referred to asnetwork function virtualization (NFV). NFV may be used to consolidatemany network equipment types onto industry standard high volume serverhardware, physical switches, and physical storage, which can be locatedin data centers, and customer premise equipment.

In the context of NFV, virtual machine 1840 may be a softwareimplementation of a physical machine that runs programs as if they wereexecuting on a physical, non-virtualized machine. Each of virtualmachines 1840, and that part of hardware 1830 that executes that virtualmachine, be it hardware dedicated to that virtual machine and/orhardware shared by that virtual machine with others of the virtualmachines 1840, forms a separate virtual network elements (VNE).

Still in the context of NFV, Virtual Network Function (VNF) isresponsible for handling specific network functions that run in one ormore virtual machines 1840 on top of hardware networking infrastructure1830 and corresponds to application 1820 in FIG. 18.

In some embodiments, one or more radio units 18200 that each include oneor more transmitters 18220 and one or more receivers 18210 may becoupled to one or more antennas 18225. Radio units 18200 may communicatedirectly with hardware nodes 1830 via one or more appropriate networkinterfaces and may be used in combination with the virtual components toprovide a virtual node with radio capabilities, such as a radio accessnode or a base station.

In some embodiments, some signalling can be effected with the use ofcontrol system 18230 which may alternatively be used for communicationbetween the hardware nodes 1830 and radio units 18200.

FIG. 19 illustrates a telecommunication network connected via anintermediate network to a host computer in accordance with someembodiments. In particular, with reference to FIG. 19, in accordancewith an embodiment, a communication system includes telecommunicationnetwork 1910, such as a 3GPP-type cellular network, which comprisesaccess network 1911, such as a radio access network, and core network1914. Access network 1911 comprises a plurality of base stations 1912 a,1912 b, 1912 c, such as NBs, eNBs, gNBs or other types of wirelessaccess points, each defining a corresponding coverage area 1913 a, 1913b, 1913 c. Each base station 1912 a, 1912 b, 1912 c is connectable tocore network 1914 over a wired or wireless connection 1915. A first UE1991 located in coverage area 1913 c is configured to wirelessly connectto, or be paged by, the corresponding base station 1912 c. A second UE1992 in coverage area 1913 a is wirelessly connectable to thecorresponding base station 1912 a. While a plurality of UEs 1991, 1992are illustrated in this example, the disclosed embodiments are equallyapplicable to a situation where a sole UE is in the coverage area orwhere a sole UE is connecting to the corresponding base station 1912.

Telecommunication network 1910 is itself connected to host computer1930, which may be embodied in the hardware and/or software of astandalone server, a cloud-implemented server, a distributed server oras processing resources in a server farm. Host computer 1930 may beunder the ownership or control of a service provider, or may be operatedby the service provider or on behalf of the service provider.Connections 1921 and 1922 between telecommunication network 1910 andhost computer 1930 may extend directly from core network 1914 to hostcomputer 1930 or may go via an optional intermediate network 1920.Intermediate network 1920 may be one of, or a combination of more thanone of, a public, private or hosted network; intermediate network 1920,if any, may be a backbone network or the Internet; in particular,intermediate network 1920 may comprise two or more sub-networks (notshown).

The communication system of FIG. 19 as a whole enables connectivitybetween the connected UEs 1991, 1992 and host computer 1930. Theconnectivity may be described as an over-the-top (OTT) connection 1950.Host computer 1930 and the connected UEs 1991, 1992 are configured tocommunicate data and/or signaling via OTT connection 1950, using accessnetwork 1911, core network 1914, any intermediate network 1920 andpossible further infrastructure (not shown) as intermediaries. OTTconnection 1950 may be transparent in the sense that the participatingcommunication devices through which OTT connection 1950 passes areunaware of routing of uplink and downlink communications. For example,base station 1912 may not or need not be informed about the past routingof an incoming downlink communication with data originating from hostcomputer 1930 to be forwarded (e.g., handed over) to a connected UE1991. Similarly, base station 1912 need not be aware of the futurerouting of an outgoing uplink communication originating from the UE 1991towards the host computer 1930.

Example implementations, in accordance with an embodiment, of the UE,base station and host computer discussed in the preceding paragraphswill now be described with reference to FIG. 20. FIG. 20 illustrateshost computer communicating via a base station with a user equipmentover a partially wireless connection in accordance with someembodiments. In communication system 2000, host computer 2010 compriseshardware 2015 including communication interface 2016 configured to setup and maintain a wired or wireless connection with an interface of adifferent communication device of communication system 2000. Hostcomputer 2010 further comprises processing circuitry 2018, which mayhave storage and/or processing capabilities. In particular, processingcircuitry 2018 may comprise one or more programmable processors,application-specific integrated circuits, field programmable gate arraysor combinations of these (not shown) adapted to execute instructions.Host computer 2010 further comprises software 2011, which is stored inor accessible by host computer 2010 and executable by processingcircuitry 2018. Software 2011 includes host application 2012. Hostapplication 2012 may be operable to provide a service to a remote user,such as UE 2030 connecting via OTT connection 2050 terminating at UE2030 and host computer 2010. In providing the service to the remoteuser, host application 2012 may provide user data which is transmittedusing OTT connection 2050.

Communication system 2000 further includes base station 2020 provided ina telecommunication system and comprising hardware 2025 enabling it tocommunicate with host computer 2010 and with UE 2030. Hardware 2025 mayinclude communication interface 2026 for setting up and maintaining awired or wireless connection with an interface of a differentcommunication device of communication system 2000, as well as radiointerface 2027 for setting up and maintaining at least wirelessconnection 2070 with UE 2030 located in a coverage area (not shown inFIG. 20) served by base station 2020. Communication interface 2026 maybe configured to facilitate connection 2060 to host computer 2010.Connection 2060 may be direct or it may pass through a core network (notshown in FIG. 20) of the telecommunication system and/or through one ormore intermediate networks outside the telecommunication system. In theembodiment shown, hardware 2025 of base station 2020 further includesprocessing circuitry 2028, which may comprise one or more programmableprocessors, application-specific integrated circuits, field programmablegate arrays or combinations of these (not shown) adapted to executeinstructions. Base station 2020 further has software 2021 storedinternally or accessible via an external connection.

Communication system 2000 further includes UE 2030 already referred to.Its hardware 2035 may include radio interface 2037 configured to set upand maintain wireless connection 2070 with a base station serving acoverage area in which UE 2030 is currently located. Hardware 2035 of UE2030 further includes processing circuitry 2038, which may comprise oneor more programmable processors, application-specific integratedcircuits, field programmable gate arrays or combinations of these (notshown) adapted to execute instructions. UE 2030 further comprisessoftware 2031, which is stored in or accessible by UE 2030 andexecutable by processing circuitry 2038. Software 2031 includes clientapplication 2032. Client application 2032 may be operable to provide aservice to a human or non-human user via UE 2030, with the support ofhost computer 2010. In host computer 2010, an executing host application2012 may communicate with the executing client application 2032 via OTTconnection 2050 terminating at UE 2030 and host computer 2010. Inproviding the service to the user, client application 2032 may receiverequest data from host application 2012 and provide user data inresponse to the request data. OTT connection 2050 may transfer both therequest data and the user data. Client application 2032 may interactwith the user to generate the user data that it provides.

It is noted that host computer 2010, base station 2020 and UE 2030illustrated in FIG. 20 may be similar or identical to host computer1930, one of base stations 1912 a, 1912 b, 1912 c and one of UEs 1991,1992 of FIG. 19, respectively. This is to say, the inner workings ofthese entities may be as shown in FIG. 20 and independently, thesurrounding network topology may be that of FIG. 19.

In FIG. 20, OTT connection 2050 has been drawn abstractly to illustratethe communication between host computer 2010 and UE 2030 via basestation 2020, without explicit reference to any intermediary devices andthe precise routing of messages via these devices. Networkinfrastructure may determine the routing, which it may be configured tohide from UE 2030 or from the service provider operating host computer2010, or both. While OTT connection 2050 is active, the networkinfrastructure may further take decisions by which it dynamicallychanges the routing (e.g., on the basis of load balancing considerationor reconfiguration of the network).

Wireless connection 2070 between UE 2030 and base station 2020 is inaccordance with the teachings of the embodiments described throughoutthis disclosure. One or more of the various embodiments improve theperformance of OTT services provided to UE 2030 using OTT connection2050, in which wireless connection 2070 forms the last segment. Moreprecisely, the teachings of these embodiments may improve thesynchronization of security states between the network and wirelessdevices, and thereby provide benefits such as avoiding the signalingrequired to correct unsynchronized security states, thereby reducingcongestion and prolonging device battery life. In some cases,embodiments of the invention may prevent a complete failure of awireless device to connect to a network.

A measurement procedure may be provided for the purpose of monitoringdata rate, latency and other factors on which the one or moreembodiments improve. There may further be an optional networkfunctionality for reconfiguring OTT connection 2050 between hostcomputer 2010 and UE 2030, in response to variations in the measurementresults. The measurement procedure and/or the network functionality forreconfiguring OTT connection 2050 may be implemented in software 2011and hardware 2015 of host computer 2010 or in software 2031 and hardware2035 of UE 2030, or both. In embodiments, sensors (not shown) may bedeployed in or in association with communication devices through whichOTT connection 2050 passes; the sensors may participate in themeasurement procedure by supplying values of the monitored quantitiesexemplified above, or supplying values of other physical quantities fromwhich software 2011, 2031 may compute or estimate the monitoredquantities. The reconfiguring of OTT connection 2050 may include messageformat, retransmission settings, preferred routing etc.; thereconfiguring need not affect base station 2020, and it may be unknownor imperceptible to base station 2020. Such procedures andfunctionalities may be known and practiced in the art. In certainembodiments, measurements may involve proprietary UE signalingfacilitating host computer 2010's measurements of throughput,propagation times, latency and the like. The measurements may beimplemented in that software 2011 and 2031 causes messages to betransmitted, in particular empty or ‘dummy’ messages, using OTTconnection 2050 while it monitors propagation times, errors etc.

FIG. 21 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 19 and 20. Forsimplicity of the present disclosure, only drawing references to FIG. 21will be included in this section. In step 2110, the host computerprovides user data. In substep 2111 (which may be optional) of step2110, the host computer provides the user data by executing a hostapplication. In step 2120, the host computer initiates a transmissioncarrying the user data to the UE. In step 2130 (which may be optional),the base station transmits to the UE the user data which was carried inthe transmission that the host computer initiated, in accordance withthe teachings of the embodiments described throughout this disclosure.In step 2140 (which may also be optional), the UE executes a clientapplication associated with the host application executed by the hostcomputer.

FIG. 22 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 19 and 20. Forsimplicity of the present disclosure, only drawing references to FIG. 22will be included in this section. In step 2210 of the method, the hostcomputer provides user data. In an optional substep (not shown) the hostcomputer provides the user data by executing a host application. In step2220, the host computer initiates a transmission carrying the user datato the UE. The transmission may pass via the base station, in accordancewith the teachings of the embodiments described throughout thisdisclosure. In step 2230 (which may be optional), the UE receives theuser data carried in the transmission.

FIG. 23 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 19 and 20. Forsimplicity of the present disclosure, only drawing references to FIG. 23will be included in this section. In step 2310 (which may be optional),the UE receives input data provided by the host computer. Additionallyor alternatively, in step 2320, the UE provides user data. In substep2321 (which may be optional) of step 2320, the UE provides the user databy executing a client application. In substep 2311 (which may beoptional) of step 2310, the UE executes a client application whichprovides the user data in reaction to the received input data providedby the host computer. In providing the user data, the executed clientapplication may further consider user input received from the user.Regardless of the specific manner in which the user data was provided,the UE initiates, in substep 2330 (which may be optional), transmissionof the user data to the host computer. In step 2340 of the method, thehost computer receives the user data transmitted from the UE, inaccordance with the teachings of the embodiments described throughoutthis disclosure.

FIG. 24 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 19 and 20. Forsimplicity of the present disclosure, only drawing references to FIG. 24will be included in this section. In step 2410 (which may be optional),in accordance with the teachings of the embodiments described throughoutthis disclosure, the base station receives user data from the UE. Instep 2420 (which may be optional), the base station initiatestransmission of the received user data to the host computer. In step2430 (which may be optional), the host computer receives the user datacarried in the transmission initiated by the base station.

Any appropriate steps, methods, features, functions, or benefitsdisclosed herein may be performed through one or more functional unitsor modules of one or more virtual apparatuses. Each virtual apparatusmay comprise a number of these functional units. These functional unitsmay be implemented via processing circuitry, which may include one ormore microprocessor or microcontrollers, as well as other digitalhardware, which may include digital signal processors (DSPs),special-purpose digital logic, and the like. The processing circuitrymay be configured to execute program code stored in memory, which mayinclude one or several types of memory such as read-only memory (ROM),random-access memory (RAM), cache memory, flash memory devices, opticalstorage devices, etc. Program code stored in memory includes programinstructions for executing one or more telecommunications and/or datacommunications protocols as well as instructions for carrying out one ormore of the techniques described herein. In some implementations, theprocessing circuitry may be used to cause the respective functional unitto perform corresponding functions, according to one or more embodimentsof the present disclosure.

Generally, all terms used herein are to be interpreted according totheir ordinary meaning in the relevant technical field, unless adifferent meaning is clearly given and/or is implied from the context inwhich it is used. All references to a/an/the element, apparatus,component, means, step, etc. are to be interpreted openly as referringto at least one instance of the element, apparatus, component, means,step, etc., unless explicitly stated otherwise. The steps of any methodsdisclosed herein do not have to be performed in the exact orderdisclosed, unless a step is explicitly described as following orpreceding another step and/or where it is implicit that a step mustfollow or precede another step. Any feature of any of the embodimentsdisclosed herein may be applied to any other embodiment, whereverappropriate. Likewise, any advantage of any of the embodiments may applyto any other embodiments, and vice versa. Other objectives, features andadvantages of the enclosed embodiments will be apparent from thedescription.

The term unit may have conventional meaning in the field of electronics,electrical devices and/or electronic devices and may include, forexample, electrical and/or electronic circuitry, devices, modules,processors, memories, logic solid state and/or discrete devices,computer programs or instructions for carrying out respective tasks,procedures, computations, outputs, and/or displaying functions, and soon, as such as those that are described herein.

Some of the embodiments contemplated herein are described more fullywith reference to the accompanying drawings. Other embodiments, however,are contained within the scope of the subject matter disclosed herein.The disclosed subject matter should not be construed as limited to onlythe embodiments set forth herein; rather, these embodiments are providedby way of example to convey the scope of the subject matter to thoseskilled in the art. The present invention may, of course, be carried outin other ways than those specifically set forth herein without departingfrom essential characteristics of the invention. The present embodimentsare to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

What is claimed is:
 1. A method of updating a security context,performed by a wireless device operative in a wireless communicationnetwork employing a Radio Resource Control (RRC) protocol, wherein thewireless device in RRC CONNECTED state receives from the network an RRCSuspend message including a security update parameter, and in responseto the RRC Suspend message enters an RRC INACTIVE state and stores afirst security context, the method comprising, upon attempting totransition to an RRC CONNECTED state: generating a second securitycontext from the security update parameter received in the RRC Suspendmessage; sending to the network an RRC Resume Request message; and inresponse to receiving from the network an RRC Reject message in responseto the RRC Resume Request message, storing the second security contextand utilizing the second security context until confirmed by thenetwork.
 2. The method of claim 1, further comprising, upon receiving anRRC message other than the RRC Reject message, discarding the firstsecurity context and using the second security context for furthercommunication.
 3. The method of claim 2, wherein the RRC message otherthan the RRC Reject message is integrity protected using the secondsecurity context.
 4. The method of claim 1, further comprising, uponreceiving an RRC Setup message indicating the wireless device is todiscard a stored Access Stratum message, discarding both first andsecond security contexts.
 5. The method of claim 1, wherein the securityupdate parameter contained in the RRC Suspend message comprises achaining counter parameter used for next hop access key derivation. 6.The method of claim 1, wherein the first and second security contextscomprise one or more cryptographic keys.
 7. The method of claim 1,further comprising, after receiving from the network an RRC Rejectmessage in response to the RRC Resume Request message, obtaining a waittime the wireless device is to wait prior to sending another RRC ResumeRequest message.
 8. The method of claim 7, wherein the wait time isincluded in the RRC Reject message.
 9. The method of claim 7, whereinthe wait time is a predetermined value.
 10. The method of claim 7,wherein the wait time is obtained from a different message received fromthe network.
 11. A method of updating a security context, performed by awireless device operative in a wireless communication network employinga Radio Resource Control (RRC) protocol, wherein the wireless device inRRC CONNECTED state receives from the network an RRC Suspend messageincluding a security update parameter, and in response to the RRCSuspend message enters an RRC INACTIVE state and stores a first securitycontext, the method comprising, upon attempting to transition to an RRCCONNECTED state: generating a second security context from the securityupdate parameter received in the RRC Suspend message; sending to thenetwork an RRC Resume Request message; and in response to expiration ofa timer started upon sending the RRC Resume Request message, withoutreceiving a responsive message from the network, storing the secondsecurity context and utilizing the second security context untilconfirmed by the network.
 12. The method of claim 11, furthercomprising, upon receiving an RRC message other than the RRC Rejectmessage, discarding the first security context and using the secondsecurity context for further communication.
 13. The method of claim 12,wherein the RRC message other than the RRC Reject message is integrityprotected using the second security context.
 14. The method of claim 11,further comprising, upon receiving an RRC Setup message indicating thewireless device is to discard a stored Access Stratum message,discarding both first and second security contexts.
 15. The method ofclaim 11, wherein the security update parameter contained in the RRCSuspend message comprises a chaining counter parameter used for next hopaccess key derivation.
 16. The method of claim 11, wherein the first andsecond security contexts comprise one or more cryptographic keys. 17.The method of claim 11, further comprising, after receiving from thenetwork an RRC Reject message in response to the RRC Resume Requestmessage, obtaining a wait time the wireless device is to wait prior tosending another RRC Resume Request message.
 18. The method of claim 17,wherein the wait time is: included in the RRC Reject message. apredetermined value; or is obtained from a different message receivedfrom the network.
 19. A method of updating a security context, performedby a wireless device operative in a wireless communication networkemploying a Radio Resource Control (RRC) protocol, wherein the wirelessdevice in RRC CONNECTED state receives from the network an RRC Suspendmessage including a security update parameter, and in response to theRRC Suspend message enters an RRC INACTIVE state and stores a firstsecurity context, the method comprising, upon attempting to transitionto an RRC CONNECTED state: generating a second security context from thesecurity update parameter received in the RRC Suspend message; sendingto the network an RRC Resume Request message; and in response toperforming a cell reselection prior to receiving a message from thenetwork responsive to the RRC Resume Request message, storing the secondsecurity context and utilizing the second security context untilconfirmed by the network.
 20. The method of claim 19, wherein thesecurity update parameter contained in the RRC Suspend message comprisesa chaining counter parameter used for next hop access key derivation.